LIBRARY 

OF   THK 

UNIVERSITY  OF  CALIFORNIA 

Received. 

Accessions  No.-&./j^  Shelf  No. 


OUTLINES 


OF 


PROXIMATE    ORGANIC    ANALYSIS, 


BY  THE  SAME  A  UTHOR. 


12mo,  cloth,  $1  50. 

CHEMICAL    EXAMINATION 

* 

ALCOHOLIC  LIQUORS. 

A  MANUAL,  OP  THE 

CONSTITUENTS    OF    THE    DISTILLED    SPIRITS 

AZTD 

FERMENTED  LIQUORS  OF  COMMERCE, 

AOT>  TBOEIB 

QUALITATIVE  AND  QUANTITATIVE  DETERMINATIONS. 


OUTLINES 


OF 


PROXIMATE   ORGANIC   ANALYSIS, 


FOB 


IDENTIFICATION,  SEPARATION,  AND  QUANTITATIVE 
DETERMINATION 


MORE  COMMONLY  OCCURRING  ORGANIC  COMPOUNDS. 


ALBERT  B. 

PEOFKSSOB  OF  OEGANIO  AND  APPLIED  CHEMI8TBY  IN  THB  UKITBBMTT  OF 

THIRD     EDITION. 

NEW  YOEK: 

D.    VAN    NOSTRAND,     PUBLISHER, 
23  MURRAY  STREET,  AND  27  WARREN  STREET. 

1882. 


Main  uS>. 
Agric.  Dept 


Entered,  according  to  Act  of  Congress,  in  the  year  1874,  by 
D.  VAN  NOSTKAND, 

y/x3^ 

In  the  Office  of  the  Librarian  of  Congress,  at  Washington,  D.  C. 


PREFACE. 


THIS  little  work  has  been  prepared  more  espe- 
cially for  the  use  of  a  class  of  chemical  students 
who  devote  a  semester  to  the  analysis  of  vege- 
table products  and  other  organic  mixtures,  taking 
previously  at  least  two  semesters  in  qualitative 
and  quantitative  analysis.  After  working  with 
this  class  for  several  years,  without  other  aid  than 
a  manuscript  digest  of  directions  and  references, 
the  author  is  convinced  that  a  compilation  in  this 
subject  is  desirable — not  alone  for  students  in 
special  applications  of  chemistry,  but  for  the  con- 
venience of  every  general  analyst. 

Proximate  organic  analysis  is  not  altogether 
impracticable,  and  organic  chemistry  is  not  solely 
a  science  of  synthetical  operations  even  at  pre- 
sent. It  is  true,  as  the  chief  analytical  chemists 
have  repeatedly  pointed  out,  that  in  the  rapid 
accumulation  of  organic  compounds  the  means 
of  their  identification  and  separation  have  been 


PREFACE. 


left  in  comparative  neglect.  It  is  true,  also,  that 
the  field  is  limitless ;  but  this  is  not  a  reason  for 
doing  nothing  in  it.  Fifty  years  ago,  the  work- 
ers in  inorganic  analysis  were  unprovided  with  a 
comprehensive  system,  but  they  went  on  explor- 
ing the  mineral  kingdom  and  using  their  scanty 
means  to  gain  valuable  results. 

That  this  compilation  is  a  fragmentary  and 
very  brief  exponent  of  this  part  of  analytical 
science  as  it  exists  at  present,  the  author  is  fully 
aware,  but  he  hopes  that,  as  a  beginning,  it  may 
prove  to  be  worth  enough  to  afford  an  opportu- 
nity for  its  improvement  hereafter. 

UNIVERSITY  OF  MICHIGAN,  September,  1874. 


CONTENTS. 


frABAGRAPH.  PAGE. 

PRELIMINARY  EXAMINATIONS. 

1.  Carbon,  uncombined,        -  11 

2.  Carbon  in  combination,     -  11 

3.  Preliminary    examination 

of  Solids,   -       -       -       -  11 

4.  Preliminary    examination 

of  Liquids,                        -  12 

5.  References  for  Solids  and 

Liquids  ;  Fixed  and  Vola- 
tile ;  Acid,  Fatty,  Basic, 

and  Neutral,                     -  13 

SOLID  NON-VOLATILE  ACIDS. 

6.  Tartaric  acid,                      -  14 

7.  Racemicacid,                      -  18 

8.  Citric  acid,  -       -       -       -  18 

9.  Aconitic  acid,                     -  21 

10.  Malic  acid,                           -  22 

11.  Meconic  acid,  24 

12.  Digitalic  acid,                     -  26 

13.  Tannicacid,                        -  26 

14.  Gallic  acid,           -       -       -  30 

15.  Pyrogallic  acid,                  -  32 

16.  Quinotannic  acid,               -  33 

17.  Catechutannic  acid,  33 

18.  Catechuic  acid,                   -  34 

19.  Morintannic  acid,       -       -  35 

20.  Caff etannic  acid,                -  35 

21.  Boheicacid,                        -  36 

22.  Quinicacid,         ...  36 


PARAGRAPH.  PAGE. 

23.  Quinovic  acid,  -  38 

24.  Columbic  acid,  -  39 

25.  Gentianic  acid,  -  39 

26.  Carminic  acid,  -  40 

27.  Chrysophanic  acid,  -  41 

28.  Gambogic  acid,  -  41 

29.  Santalic  acid,  -  42 

SOLID  VOLATILE  ACIDS. 

30.  Benzoicacid,  -  42 
81.  Cinnamic  acid,  -  44 

32.  Succinic  acid,  -  45 

33.  Salicylic  acid,     -  -       -  47 

34.  Veratric  acid;  -  47 

35.  Phenicacid,         -  -  48 

36.  Nitrophenic  acid,  -  51 

37.  Sulphophenic  acid,  -       -  53 

LIQUID  NON-VOLATILE  ACID. 

38.  Lactic  acid,  -  53 

LIQUID  VOLATILE  ACIDS. 

39.  Formic  acid,  -  55 

40.  Acetic  acid,  -       -  58 

41.  Butyric  acid,  -  61 

42.  Valeric  acid,  -  63 

43.  Separations,  -  67 

44.  Volatile  Fat  Acids  of  the 

acetic  series,  -  67 


CONTENTS. 


PABAGBAPH.  PAGE. 

FATTY  ACIDS  :  LIQUID  AND  SOLID. 

45.  Non-Volatile  Fatty  Acids,  68 

46.  Bicinoleic  acid,                   -  69 

47.  Oleicacid,                            -  69 

48.  Linoleic  acid,                      -  69 

49.  Erucicacid,         -       -       -  70 

50.  Laurie  acid,         -       -       -  70 

51.  Myristic  acid,      -       -  70 

52.  Palmitic  acid,                     -  70 

53.  Stearic  acid,        -       -       -  70 

54.  Cerotic  acid,                -       -  70 

55.  Separations  by  Saponifica- 

tion,    -----  71 

56.  Separations  by  Fusion,      -  71 

57.  Separations  by  Solvents,   -  71 

58.  Quantitative      Determina- 

tions, -----  72 

NEUTRAL  SUBSTANCES  :   LIQUID  OB 
FUSIBLE. 

59.  Fixed  Oils:  (a)  Liquid;  (6) 

Solid,                                 -  72 

60.  Methods  of  Examination 

of  Fixed  Oils,    -       -       -  74 

61.  Calvert's  Methods,             -  78 

62.  Tests   with    Argentic  Ni- 

trate,    81 

63.  Analysis  of  Butter,     -       -  81 

64.  Analysis  of  Milk,        -       -  84 

65.  Separation  of  Fixed  from 

Volatile  Oils,                     -  85 

66.  Glycerin,      -       -       -       -  85 

67.  Methods    of     Analysis    of 

Soaps,  87 

68.  Resins :  general  character- 

istics, -----  92 

69.  Resins  :    how    separated 

from  other  bodies,  93 

70.  Aloes  resin,                          -  93 

71.  Amber  resin,       -  93 

72.  Ammoniac  resin,        -  94 

73.  Assafetida  resin,  94 

74.  Benzoin  resin,  94 

75.  Canaubawax,     -       -       -  95 


PAGE. 

-  95 

-  95 

-  96 


PABAGBAPH. 

76.  Caoutchouc,         - 

77.  Colophony,  - 

78.  Copaiba  resin, 

79.  Copal  resin, 

80.  Dammara  resin,  - 

81.  Dragon's  Blood  resin, 

82.  Gamboge  resin,   - 

83.  Guaiacum  resin,  - 

84.  Hemp  resin, 

85.  Indigo-blue  resin, 

86.  Jalap  resin,         - 

87.  Jalapin  resin, 

88.  Convolvulin  resin, 

89.  Lac  resin,    - 

90.  Mastic  resin, 

91.  Myrrh  resin,        - 

92.  Olibanum  resin,  - 

93.  Peru  balsam  resin, 

94.  Podophyllum  resin,    - 

95.  Sandarac  resin,  - 

96.  Scammony  resin, 

97.  Storax  resin, 

98.  Tolu  balsam  resin, 

99.  Separation  of  Resins, 

100.  Volatile  Oils :  Classes  of,    - 

101.  '  Properties  of, 

102.  '  Solubilities  of,    - 

103.  '  How  identified,  - 

104.  '  How  separated,  - 

105.  '  List,  with   color 

andsp.  gr.,       -    107 

106.  Examination  by  Alcohol,  -    108 

107.  Examination     by     Iodine 

and  Bromine,    -  109 

108.  Examination  by  sulphuric 

acid,  etc.,  -  111 

109.  Examination  by  Plumbic 


sulphide,  - 


97 
97 

98 
98 


100 
100 
101 
101 
103 
103 
102 
102 
102 
102 
103 
103 
104 
104 
105 
105 
105 


-    114 


110.  Examination  by  Sodium,  -  114 

111.  Resinified  Volatile  Oils,  -  115 

112.  Turpentine  oil,    -  -  115 

113.  Valerian  oil,        -       -  115 

114.  Peppermint  on,  -  -  115 

115.  Camphor,    -  -  116 

116.  Creosote,      -  -  116 


CONTENTS. 


PABA.GKAPH.  PAGE. 

117.  Anthracene,         -  117 

118.  Alizarin,       -        -        -       -  117 

119.  Benzole;  Petroleum,  Naph- 

tha,    -----  118 

120.  Nitrobenzole,               -       -  119 

BASES  :  LIQUID  AND  SOLID. 

121.  Anilin,                                  -  120 

122.  Anilin  of  commerce,  -       -  120 

123.  Anilin  Compounds,    -        -  121 

124.  Toluidin,      -       -       -       -  121 

125.  Methods   of    Determining 

Anilin,        -                         -  121 

126.  Alkaloids :  classes  of,        -  123 

127.  Conia,  -        -        -                -  123 

128.  Lobelina,                     -       -  123 

129.  Nicotia,        -                       -  123 

130.  Trimethylamia,  -       -       -  123 

131.  Comparative  reactions  of 

Volatile  bases,  -       -       -  124 

132.  Non-  Volatile  Alkaloids: 

List, 125 

133.  Table  of  Solubilities  of,     -  128 
134  Separation  of ,    -       -       -  130 

(1)  Method  of  Stas-Otto,         -  131 

(2)  Rodgers  and  Girdwood,    -  132 

(3)  Uslar  and  Erdmann,         -  133 

(4)  Graham  and  Hofmann,    -  134 

(5)  by  Dialysis,        -       -       -  134 

(6)  Method  of  Dragendorff,   -  134 

(7)  Dragendorff  (Alkaloids  and 

Glucosides),     -       -       -  136 

(8)  by  use  of  Alkalies,     -       -  137 

(9)  Ether,  Water,  Chloroform,  138 

135.  Identification  as  Alkaloids,  139 
a.  by  Potassio  Mercuric  Io- 
dide,        -       -       -       -  139 

6.  Phosphomolybdic  acid,      -  140 

c.  Metatungstic  acid,      -       -  141 

d.  Potassio  Cadmic  Iodide,    -  141 

e.  Picric  acid,                           -  142 
/.  Tannicacid,         -        -         .143 
g.  Iodine  in  Iodide,         -       x  144 

136.  Alkaloids  with   Sulphuric 

acid  and  Frohde's  reagent,  144 


PAEAGEAPH.  PAGB. 

137.  Sulphuric     and    Chromic 

acids,  -    146 

138.  Nitric  acid,  -       -       -       -    146 

139.  Sulphuric  acid  and  Nitrate,    147 

140.  Chlorine,  then  Ammonia,  -  .  148 

141.  Ferric  Chloride,  -    148 

142.  Platinic  Chloride  (Quanti- 

tative), -    148 

143.  Auric  Chloride  (Quantita- 

tive), -  -       -    150 

GLUCOSIDES  AND  OTHER  SOLID  NEU- 
TRAL SUBSTANCES. 

144.  Absinthin,    -  -       -       -  151 

145.  Aloin,  -       -  -  151 

146.  Amygdalin,  -  152 

147.  Asparagin,  -  -  152 

148.  Cantharidin,  -       -  153 

149.  Cathartin,    -  -  153 

150.  Colombin,    -  -       -       -  153 

151.  Cubebin,       -  -               -  154 

152.  Elaterin,      -  —      -  154 

153.  Fraxin,  -  154 

154.  Lactucin,  -       -  155 

155.  Phloridzin,  -  -  155 

156.  Populin,  -  155 

157.  Quassin,       -  -               -  155 

158.  Sarsaparillin,  -  156 

159.  Taraxacin,  -  -  156 

160.  Vanillin,      -  -  156 

161.  Separation  of  Glucosides, 

etc.,    -       -       -       -        -    156 

NITROGENOUS  NEUTRAL  BODIES. 

162.  Albumenoids,      -       -       -  157 

163.  Ovalbumen,  -  158 

164.  Seralbumen,        -       -  -     -  158 

165.  Casein,         -       -       -       -  159 

166.  Milk  Albumen,    -       -       -  159 

167.  Determ.  Casein  and  Albu- 

men in  Milk,      -       -       -    159 

168.  Quantitative  Anal,  of  Milk,    160 

169.  Commercial   Examination 

of  Milk,      -       -       -       -    160 


10 


CONTENTS. 


PARAGRAPH. 

170.  Gelatin, 

171.  Leather,       -       -       - 

CARBOHYDRATES. 

172.  Gums,  - 

173.  Gum  Arabic, 

174.  Gum  Tragacanth, 

175.  Dextrin,       - 

176.  Starch,         -       -       - 

177.  Pectous  Substances,    - 

178.  Pectose, 

179.  Pectin,         -       -       - 

180.  Pectic  acid,  -       -       - 

181.  Parapectin,  - 
183.  Parapectic  acid,  - 

183.  Metapectin, 

184.  Metapectic  acid, 

185.  Cellulose,     -       -       - 

186.  Nitrocellulose,    - 


PAGE. 

PARAGRAPH. 

PAGE. 

-      160 

187.  Glucose, 

-      168 

-    161 

188.  Lactose,        - 

-    171 

189.  Sucrose, 

-    172 

190,  Mannite,       - 

-    174 

-    161 
-    162 

ALCOHOLS  AND  THEIR  PRODUCTS. 

-    162 

191.  Methylic  Alcohol,       -. 

-    175 

-    163 

192.  Ethylic  Alcohol, 

-    176 

-    163 

193.  Aldehyde,    - 

-    177 

-    166 

194.  Sulphethylates,  - 

-    177 

-    166 

195.  Ether,  - 

-    179 

-    166 

196.  Nitrous  Ether,     - 

-    180 

-    166 

197.  Chloroform, 

-    180 

-    166 

198.  Chloral  Hydrate, 

-    182 

-    166 

199.  lodoform,     - 

-    184 

-    167 

200.  Croton  Chloral  Hydrate, 

-    184 

-    167 

201.  Amylic  Alcohol, 

-    184 

-    167 

202.  Fusel-Oil,      - 

-    185 

-    168 

203.  Nitrite  of  Amyl, 

-    186 

OUTLI 


OF 


PROXIMATE   ORGANIC   ANALYSIS. 


PRELIMINARY   EXAMINATIONS. 

1.  CARBON  (uncombined)  is  recognized  by  its  sensible  pro- 
perties (as  charcoal,  graphite,  or  diamond),  by  not  vaporizing 
when  heated,  and  by  resisting  ordinary  solvents — neutral,  alka- 
line or  acid — except  that  graphite  is  oxidized  by  digestion  with 
chlorates  and  sulphuric    or    hydrochloric  acid,  or  with  bichro- 
mates and  sulphuric  acid,  or  with  mixed  nitric  andT  sulphuric 
acids. — Also,  on  ignition  in  the  air,  or  in  a  close  tube  with  oxide 
of  copper,  carbonic  anhydride  is  obtained  from  carbon  alone,  as 
well  as  from  its  compounds. 

2.  THE    COMPOUNDS    OP  CARBON— except  the  alka- 
line carbonates — yield  carbonic  anhydride  when  ignited  in  the  air 
or  in  a  tube  with  supply  of  oxygen  (as  with  dry  oxide  of  copper). 
The  non-volatile  "  Organic  "  Compounds  of  Carbon  leave  a  resi- 
due of  carbon  after  partial  combustion — i.e.,  they  carbonize  by 
ignition. 

3.  Preliminary  examination  OF  SOLIDS  to  determine 
whether  inorganic  or  organic,  or  both. 

a.  Heat  gradually,  to  prolonged  ignition,  in  a  glass  tube  open 
at  both  ends,  or  on  platinum  foil. 

(1)  The  substance  is  permanent:  Inorganic. 

(2)  Carbonizes  and  burns  away,  leaving  no  residue :  Organic. 
See  5,  a.  n 


12  PRELIMINARY   EXAMINATIONS. 

(3)  Carbonizes  and  leaves  a  fixed  residue :  Organic  and  Inor- 
ganic.    See  c. 

(4)  There  is  doubt  as  to  carbonization :  test  according  to  b. 

(5)  The  substance  vaporizes — wholly  or  partly  :  test  accord- 
ing to  b.     Also  consider  ammonium  salts,  the  volatile  elements, 
and  the  inorganic  volatile  acids,  oxides,  sulphides,  etc.     Examine 
according  to  4,  b. 

b.  Mix  the  (dry)  substance  (free  from   carbonates  yielding 
COa  on  ignition)   with  dry  oxide   of  copper ;    introduce  into  a 
short  combustion-tube  or  a  hard-glass  test-tube ;  connect,  by  a 
cork  and  bent  narrow  tube,  with  a  solution  of  lime  or  baryta,  or 
basic  acetate  of  lead,  and  ignite.     If  a  precipitate  is  formed,  test 
it  as  a  carbonate. 

c.  Ignite  a  portion  in  a  porcelain  capsule,  until  free  from  car- 
bon— cooling  and  adding  a  drop  or  two  of  concentrated  nitric 
acid  from  time  to  time,  if  necessary  to  facilitate  the  combustion. 
Submit  the  residue  to  inorganic  analysis.     Examine  another  por- 
tion for  organic   bodies — applying  the  solvents,  as  in  134  (9) 
or  (7).     For  an  index  of  some  of  the  most  common  organic 
solids,  see  5,  a. 

4.  Preliminary  examination  of  LIQUIDS,  to  determine 
whether  partly  or  wholly  organic  or  not,  and  to  separate 
dissolved  solids. 

a.  Evaporate  a  portion,  on  a  slip  of  glass,  at  a  very  gentle 
heat.     If,  after  cooling,  a  solid  residue  is  obtained,  test  it  accord- 
ing to  3.     If  there    is   an   insufficient  residue,  obtain  for   this 
examination  a  larger  quantity  by  distillation,  as  directed  in  b. 

b.  Distil  from  a  small  retort  or  connected  flask,  admitting  a 
thermometer,  using  a  very  gradually-increasing  heat,  and  chang- 
ing the  receiver  as  often  as  the  boiling  point  is  seen  to  rise. 
Cool  the  residue  and  distillates.     Test  the  solid  portions  accord- 
ing to  3 ;    the  liquid  portions,  also,  according  to  3,  a  or  b — then 
referring  as  indicated  in  the   next   paragraph.     For    index   of 
Organic  Liquids,  see  5,  b. 


PRELIMINAR  Y   EXAMINA  TIONS. 


13 


5.  a.  SOLIDS. 


NON-VOLATILE. 


Acids:  Aconitic — 9. 

Boheic— 21. 

Caffetannic— 20. 

Catechuic— 18. 

Catechutannic — 17. 

Carminic— 26. 

(Chrysophanic) — 27. 

Citric— 8. 

Columbic— 24. 

Digitalic— 12. 

(Gallic)— 14. 

Gambogic — 28. 

Gentianic — 25. 

Malic— 10. 

Meconic — 11. 

Morintannic — 19. 

(PyrogaUic)— 15. 

Quinic— 22. 

Quinotannic — 16. 

Quinovic— 23. 

Racemic — 7. 

Tannic— 13. 

Tartaric— 6. 

Santalic— 29. 
Fatty  Acids : 

Cerotic— 54. 

Erucic  (melts  at  34°  C.)— 49. 

Laurie — 50. 

Myristic— 51. 

Palmitic--52. 

Stearic— 53. 
Fixed  salts  of  volatile  acids. 


Fixed  Oils— 59,  b ;  60  to  63. 


Resins— 99,  and  68  to  98. 
Alkaloids  (fixed)— 132  to  143. 
Carbohydrates  : 

Cellulose— 185. 

Dextrin— 175. 

Gum— 172. 

Gun-cotton— 186. 

Pectin,  etc.— 177  to  184. 

Starch— 176. 

Sugars— 187  to  190. 
Albumenoids— 162  to  167. 
Gelatin— 170,  171. 

VOLATILE. 
Acids :  Benzoic— 30. 

(Chrysophanic)— 27. 

Cinnamic — 31. 

(Gallic)— 14. 

Nitrophenic— 36. 

(PyrogaUic)— 15. 

Salicylic— 33. 

Succmic— 32. 

Sulphophenic — 37. 

Veratric— 34. 

Camphors— 115,  101,  and  111. 
Anthracene — 117. 
Alizarin — 118. 
Anilin  compounds — 123. 
Chloral  hydrate— 198. 
lodoform— 199. 
Salts  of  Volatile  Alkaloids, 


b.  LIQUIDS. 


NON-VOLATILE. 
Acid :  Lactic— 38. 
Fatty  Acids  : 

Linoleic  (melts,  18°  C.)-48. 

Oleic— 47. 

Ricinoleic — i6. 
Fixed  Oils— 59. 
(Soft  Soaps)— 67. 
Glycerin— 66. 


VOLATILE. 
Acids:  Acetic— 40. 
Butyric — 41. 
Formic— 39. 
Valeric— 42. 

Volatile  Oils— 105, 104,  and  100  to  114. 
Creosote— 116. 

Volatile  Alkaloids— 131  and  126  to 
130. 


14  SOLID   NON-VOLATILE  ACIDS. 


Anilin— 121. 


Solvents:  Ether-195. 


Solvents— Continued. 


Co.    Ethers— 406,    416,    42a, 

44,  etc. 

Meth.  Alcohol— 191. 
Nitrobenzole— 120. 
Petroleum— 


Alcohol— 193. 
Aldehyd— 193. 
Amyl.  Alcohol— 201. 
Benzole— 119. 
Chloroform— 197. 


SOLID    NON-VOLATILE    ACIDS. 

6.  TART  ABIC  ACID.  H2C4H4O6.  Characterized  by  the 
form  of  its  crystals  and  its  rotation  of  polarized  light  (a) ;  by  its 
odor  when  heated,  and  its  color  when  treated  with  sulphuric 
acid  (b) ;  by  the  properties  of  its  salts  of  calcium,  potassium, 
lead,  and  silver  (c) ;  by  the  extent  of  its  reducing  power  (d). — 
Separated  (as  free  acid)  from  salts  or  other  substances  insoluble 
in  alcohol  by  its  solubility  in  that  menstruum,  and  from  aqueous 
solutions  by  its  solubility  in  amyl-ic  alcohol  (e) ;  from  alcoholic 
solutions  by  the  insolubility  of  tartrates  in  alcohol  (c) ;  from 
citric  acid  by  the  precipitation  of  calcium  tartrate  in  cold  water 
and  of  potassium  tartrate  in  aqueous  alcohol  (c) ;  from  sub- 
stances not  precipitable  by  oxide  of  lead  by  the  method  given 
under  Acetic  acid  at  g  (40). — Determined  by  acidimetry  (f) ; 
gravimctrically  as  lead,  calcium,  or  potassium  tartrate  (g) ;  by. 
sp.  gr.  of  water  solutions  (see  Storer's  "  Dictionary  of 
Solubilities  "). 

a.  Ordinary   tartaric   acid,  or   "  dextrotartaric   acid,"  crys- 
tallizes  in    colorless,    transparent,    hard,    monoclinic    (oblique 
rhombic)  prisms,  permanent  in  the  air,  soluble  in  1.5  parts  cold 
water,  0.5  part  hot  water,  3  parts  alcohol,  not  soluble  in  ether. 
The  solution  rotates  the  plane  of  polarized  light  to  the  right. 

b.  When  heated  to  170°  to  180°  C.,  the  crystals  melt  with 
formation  of  metatartaric  acid,  etc. ;  by  higher  heat  in  the  air, 
various  distillation  products  are  generated,  and  the  mass  burns 
with  the  odor  of  burnt  sugar  and  the  separation  of  carbon. — 


TARTARIC    ACID.  15 

Pure  tartaric  acid  dissolves  in  cold  concentrated  sulphuric  acid, 

colorless,  the  solution  turning  black  when  warmed. 

c.  The  normal  tartrates  of  potassium,  sodium,  and  ammo- 
nium, and  the  acid  tartrate  of  sodium,  are  freely  soluble  in 
water ;  the  acid  tartrates  of  potassium  and  ammonium  are  spar- 
ingly soluble  in  water ;  the  normal  tartrates  of  non-alkaline 
metals  are  insoluble  or  only  slightly  soluble  in  water,  but  mostly 
dissolve  in  solution  of  tartaric  acid.  Tartrates  are  insoluble  in 
absolute  alcohol.  Aqueous  alkalies  dissolve  most  of  the  tartrates 
(those  of  mercury,  silver,  and  bismuth  being  excepted),  generally 
by  formation  of  soluble  double  tartrates.  For  this  reason, 
tartaric  acid  prevents  the  precipitation  of  salts  of  iron  and  many 
other  heavy  oxides  by  alkalies.  Hydrochloric,  nitric,  and 
sulphuric  acids  decompose  tartrates. 

A  solution  of  tartaric  acid  added  to  cold  solution  of  lime, 
leaving  the  reaction  alkaline,  causes  a  slight  white  precipitate  of 
calcic  tartrate  (distinction  from  Citric  acid,  which  precipitates 
only  when  heated).  The  same  precipitate  is  produced  with  a 
tartrate  and  calcic  chloride  solution ;  but  not  readily,  if  at  all, 
with  free  tartaric  acid  and  calcic  sulphate  solution  (distinction 
from  Racemic  acid).  The  precipitate  of  calcic  tartrate  is  soluble 
in  cold  solution  of  potassa,  is  precipitated  gelatinous  on  boiling, 
and  again  dissolves  on  cooling  (distinctions  from  Citrate),  and  is 
dissolved  by  acetic  acid  (distinction  from  Oxalate). 

Solution  of  potassa,  or  potassic  acetate,  precipitates  concen- 
trated solutions  of  tartaric  acid,  as  the  acid  tartrate  of  potassium 
in  microscopic  crystals  of  the  trimetric  system,  soluble  in  alkalies 
and  in  mineral  acids,  not  soluble  by  acetic  acid.  The  precipitate 
is  soluble  in  230  parts  of  water  at  15°,  or  in  15  to  20  parts  of 
boiling  water,  but  insoluble  in  alcohol,  the  addition  of  which 
promotes  its  formation  in  water  solutions  (distinction  and  sepa- 
ration from  Citric,  Oxalic,  and  Malic  acids). — Tartaric  acid  is 
distinguished  from  citric  acid,  in  crystal,  and  the  former  is 
detected  in  a  crystalline  mixture  of  the  two  acids,  as  follows :  * 
*  Hager's  "Untersuchungen,"  B.  2,  S.  103. 


1C  SOLID  NON-VOLATILE  ACIDS, 

A  solution  of  4  grammes  of  dried  potassa  in  60  cubic  centi- 
meters of  water  and  30  cubic  centimeters  of  90  per  cent,  alcohol 
is  poured  upon  a  glass  plate  or  beaker-bottom  to  the  depth  of 
about  0.6  centimeter  (one-fourth  inch).  Crystals  of  the  acid 
under  examination  are  placed,  in  regular  order,  three  to  five  cen- 
timeters (one  to  two  inches)  apart,  in  this  liquid,  and  left  without 
agitation  for  two  or  three  hours.  The  citric  acid  crystal  dissolves 
slowly  but  completely  and  without  losing  its  transparency. 
The  tartaric  acid  crystal  (or  the  crystal  containing  tartaric  acid) 
becomes,  in  a  few  minutes,  opaque  white  (in  a  greater  or  less 
degree),  and  continues  for  hours  and  days  slowly  to  disintegrate 
without  dissolving  and  with  gradual  projection  of  spicate  crystals, 
fibrous  and  opaque,  also  trimetric  prisms.  (See,  also,  Citric 
acid,  e.) 

Solution  of  lead  acetate  precipitates  free  tartaric  acid  or  tar- 
trates  as  white  normal  tartrate  of  lead,  very  slightly  soluble  in 
water,  insoluble  in  alcohol,  but  slightly  soluble  in  acetic  acid, 
readily  soluble  in  tartaric  acid  and  in  tartrate  of  ammonium 
solution,  and  freely  soluble  in  ammoniacal  solution  of  tartrate  of 
ammonium  (distinction  from  Malate),  somewhat  soluble  in 
chloride  of  ammonium. 

Solution  of  silver  nitrate  precipitates  solutions  of  normal 
tartrates  (not  free  tartaric  acid)  as  white  argentic  tartrate,  soluble 
in  ammonia  and  in  nitric  acid.  On  boiling,  the  precipitate  turns 
black,  by  reduction  of  silver,  some  portion  of  which  usually 
deposits  as  a  mirror-coating  on  the  glass.  The  mirror  is  formed 
more  perfectly  if  the  washed  precipitate  of  argentic  tartrate  is 
treated  with  ammonia  just  enough  to  dissolve  nearly  all  of  it, 
and  the  solution  left  on  the  water  bath.  (The  reduction  is  a 
distinction  from  Citrate).  Free  tartaric  acid  does  not  reduce 
silver  from  its  nitrate. 

d.  The  copper  sulphate  with  potassa  is  not  reduced  by  tar- 
taric acid.  Potassium  permanganate  solution  is  reduced  very 
slowly  by  free  tartaric  acid ;  but  quickly  by  alkaline  solution  of 
tartrates,  with  separation  of  brown  binoxide  of  manganese  (dis- 


TARTABIC    ACID.  17 

tinction  from  Citrates  which  separate  the  brown  binoxide  of  man- 
ganese slowly  or  not  at  all,  leaving  green  solution  of  manganate). 

e.  Tartaric  acid  may  be  extracted  from  tartrates  by  decom- 
posing with  sulphuric  acid  and  dissolving  with  alcohol,  sulphates 
being  generally  insoluble  in  alcohol.  Free  tartaric  acid  may 
be  extracted  from  water  solutions  by  agitation  with  amylic 
alcohol,  which  rises  to  the  surface. 

Quantitative. — -f.  Free  tartaric  acid,  unmixed  with  other 
acids,  may  be  determined  volumetrically  by  adding  a  normal 
solution  of  soda,  to  the  neutral  tint  of  litmus.  Weighing  7.500 
grammes,  the  required  number  of  cubic  centimeters  of  normal 
solution  equals  the  number  per  cent,  of  acid. 

g.  In  absence  of  acids  forming  insoluble  lead  salts,  tartaric  acid 
may  be  precipitated  by  acetate  of  lead  solution,  washed  with 
dilute  alcohol,  dried  on  the  water  bath  and  weighed  as  normal 
lead  tartrate.  PbC4H4O6  :  H2C4H4Oa  :.:_!:  0.422535. 

In  absence  of  acids  forming  insoluble  calcium  salts,  tartaric 
acid  may  be  precipitated  from  solution  of  neutral  sodium  tar- 
trate by  chloride  of  calcium,  If  ammonium  salts  are  present, 
the  ammonia  should  first  be  mostly  expelled  by  adding  sodium 
carbonate  and  heating — the  excess  of  carbonate  being  neutralized 
with  acetic  acid.  The  precipitate  of  calcium  tartrate  should  be 
heated  and  left  aside  for  completion,  washed  with  a  little  water 
and  then  with  dilute  alcohol,  and  dried  (in  a  tared  filter)  at  40° 
to  50°  C.  Ca  C4H4O6+4H2O  :  H2C4H4O6  :  :  1  :  0.577. 

In  presence  of  citric  acid,  oxalic  acid,  sulphuric  acid,  phos- 
phoric acid,  etc.,  the  tartaric  acid  may  be  determined  as  potas- 
sium bitartrate.  The  solution  of  acid  is  made  nearly  neutral  by 
addition  of  soda,  or  the  solution  of  salt  (tartrate)  is  made  slightly 
acid  by  addition  of  acetic  acid ;  this  water  solution  is  obtained 
in  concentrated  form  and  treated  with  a  little  alcohol  but  not  to 
cause  a  precipitate,  and  then  precipitated  with  concentrate,!  solu- 
tion of  acetate  of  potassium.  The  precipitate  is  washed  with 
alcohol,  and  dried  on  the  water  bath.  KH  C4H4O6  :  H3C4H4O6 
:  :  1 :  0.797.  Results  approximate. 


18  SOLID  NON- VOLATILE  ACIDS. 

7.  KACEMIC  ACID.     Isomer  of  tartaric  acid,  from  which 
it  is  distinguished  as  follows:    By  forming   triclinic  crystals., 
H2C4H4O6 .  H8O ;  soluble  in  5  parts  cold  water  or  48  parts  of 
alcohol  of  sp.  gr.  .809 ;  slightly  efflorescent  on  the  surface  ;  losing 
the  water  of  crystallization  at  100°.     By  its  solution  (uncom- 
bined)  being  able  to  form  after  a  short  time  a  slight  precipitate 
in  solution  of  calcic  sulphate  and  a  precipitate  in  solution  of 
calcic  chloride ;  the  precipitate  of  calcic  racemate  being,  after 
solution  in  hydrochloric  acid,  precipitated  again   by  ammonia, 
that  is,  not  soluble  in  chloride  of  ammonium  solution.     By  being 
inactive  toward  polarized  light, 

8.  CITRIC  ACID.    H3C6H5O7.     Characterized  by  the  form, 
solubilities,  and  fusibility  of  its  crystals  (a) ;  by  the  properties 
of  its  salts  of  calcium,  barium,  lead,  silver,  potassium  (Z>) ;  by  the 
limits  of  its  reducing  power  (c). — Separated  (as  free  acid)  from 
sulphates  and  other  substances  insoluble  in  alcohol  by  its  solu- 
bility in  this  menstruum  (c? ) ;  from  tartaric  acid,  approximately, 
by  the  slight  solubility  of  the  potassic  tartrate  in  dilute  alcohol 
(e) ;  from  acids  which  form  soluble  lead  salts  by  method  given 
under  Acetic  acid  at  g. — Determined  by  acidimetry  (/) ;  by 
precipitation  as  barium  citrate  to  be  weighed  as  barium  sulphate, 
or  as  barium  citrate. 

a.  The  citric  acid  of  commerce  is  crystallized  (from  rather 
concentrated  solutions)  as  H3C6H6O7  .  H2O,  in  large,  transparent, 
colorless,  and  odorless  prisms  of  the  trimetric  system.  These 
crystals  slowly  effloresce  in  the  air  between  28°  and  50°  C.,  and 
lose  all  their  water  of  crystallization  at  1 00°  C.  A  different  form 
of  crystals,  containing  one  molecule  of  water  to  two  molecules 
of  acid,  is  obtained  from  boiling,  concentrated  solutions. — Citric 
acid  melts  when  heated,  and  at  175°  gives  off  pungent,  character- 
istic vapors,  containing  acetone  (see  Acetic  acid,  40,  c),  while 
Aconitic  acid  (9)  is  formed  in  the  residue.  (The  odor  is  dis- 
tinctly unlike  that  of  heated  Tartaric  acid.) — Citric  acid  is 
soluble  in  less  than  its'  weight  of  water,  in  1 .5  parts  of  90  per 


CITRIC  ACID.  19 

cent,  alcohol,  insoluble  in  absolute  ether,  but  soluble  to  a  slight 
extent  in  ether  containing  alcohol  or  water ;  also  slightly  soluble 
in  chloroform  containing  alcohol. 

b.  The  alkaline  citrates  are  freely  soluble  in  water ;  iron,  zinc, 
and  copper  citrates,  moderately  soluble ;  other  metallic  citrates 
mostly  insoluble,  calcium  citrate  being  somewhat  soluble  in  cold 
water,  but  nearly  insoluble  in  hot  water.    Ammonio-ferric  citrate 
is  readily  soluble  in  water.     Citric  acid  prevents   the  precipita- 
tion of  iron  and  many  other  heavy  metals  by  the  alkalies,  soluble 
double  citrates  being  formed.    The  alkaline  citrates  are  sparingly 
soluble  in  hot,  less  soluble  in  cold  alcohol. — Solution  of  lime, 
added  to  solution  of  citric  acid  or  citrates,  causes  no  precipitate 
in  the  cold   (distinction  from  Tartaric,  Kacemic,  Oxalic  acids) ; 
but  on  boiling  a  slight  precipitate  is  formed  (distinction  from 
Malic  acid).     Solution  of  chloride  of  calcium  does  not  precipi- 
tate solution  of  free  citric  acid  even  on  boiling,  nor  citrates  in  the 
cold,  but  precipitates  citrates  (neutralized  citric  acid)  when  the 
mixture   is   boiled.      The    precipitate,    Ca3(CcH5O7)2 .  2H2O,   is 
insoluble  in  cold  solution  of  potassa  (which  should  be  not  very 
dilute  and  nearly  free  from  carbonate),  but  soluble  in  solution  of 
cupric  chloride  (two  means  of  distinction  from  Tartaric  acid) ; 
also    soluble    in    cold   solution  of  chloride    of  ammonium    and 
readily  soluble  in  acetic  acid. — Solution  of  acetate  of  lead  pre- 
cipitates from  solutions  of  neutral  citrates,  and  from  even  very 
dilute  alcoholic  solution  of  citric  acid,  the  white  citrate  of  lead, 
Pb3(C6H&O7)2.|-H2O,    somewhat    soluble     in    free     citric     acid, 
soluble  in  nitric  acid,  in  solutions  of  all  the  alkaline  citrates  and 
of  chloride  and  nitrate  of  ammonium,  soluble  in  ammonia  (for- 
mation of  basic  citrate  of  lead  then  soluble  with  the  citrate  of 
ammonium  produced).     (Malate  of  lead  is  not  soluble  in  malate 
of  ammonium.) 

c.  Nitrate  of  silver  precipitates  from    neutral   solutions  of 
citrates,  white  normal  citrate  of  silver,  not  blackened  by  boiling 
(distinction    from    Tartrate). — Solution    of   permanganate    of 
potassium  is  scarcely  at  all  affected  by  free  citric  acid  in  the  cold. 


20  SOLID   N ON- VOLATILE  ACIDS. 

With  free  alkali,  the  solution  turns  green  slowly  in  the  cold, 
readily  when  boiled,  without  precipitation  of  brown  binoxide  of 
manganese  till  after  a  long  time  (distinction  from  Tartrate). 

d.  Citric  acid  is   separated  from  "  extractive  matters "  and 
from  acids  which  form  soluble  barium  salts  by  precipitation,  as 
barium  citrate,  which  is  then  carefully  decomposed  with  sul- 
phuric acid. — From  citrates  soluble  in  water,  the  acid  may  be 
obtained   by  decomposing  with  sulphuric  acid  (not  added   in 
excess),  then  removing  the  water  by  evaporation  at  a  tempera- 
ture below  100°,  and  extracting  the  citric  acid  from  the  residue 
by  alcohol. 

e.  One  part  of  citric  acid  dissolved  in  two  parts  of  water, 
and  treated  with  a  solution  of  one  part  of  acetate  of  potassium 
in  two  parts  of  water,  will  remain   clear  after  addition  of  an 
equal  volume  of  strong  alcohol  (absence  of  Tartaric,  Eacemic, 
and  Oxalic  acids).     For  a  method  by  treatment  of  the  crystals 
with  alcoholic  solution  of  potassa,  see  Tartaric  acid  (1),  c. 

Quantitative. — -f.  Uncombined  citric  acid,  not  mixed  with 
other  acids,  may  be  determined  volumetrically  by  adding  a 
standard  solution  of  soda  or  potassa  to  the  neutral  tint  of  litmus. 
Weighing  7.000  grammes  (fa  of  |  of  C6H8O7  .  H2O)  the  number 
of  cubic  centimeters  of  normal  solution  of  alkali  required  equals 
the  number  per  cent,  of  crystallized  acid.* 

g.  The  precipitation  of  alkaline  citrates  by  barium  acetate  is 
made  complete  in  solution  of  alcohol  of  sp.  gr.  0.908 — as 
follows  :f 

The  citric  acid  is  obtained  as  alkaline  citrate ;  if  free,  by  neu- 
tralization with  soda ;  if  combined  with  a  non-alkaline  base,  by 
warm  digestion  with  an  excess  of  soda  or  potassa,  filtering  and 
washing — the  filtrate  being  neutralized  by  acetic  acid.  In  either 
case,  the  carefully  neutralized  and  not  very  dilute  solution  is 
treated  with  a  slight  excess  of  exactly  neutral  solution  of  acetate 
of  barium,  and  a  volume  of  95  per  cent,  alcohol,  equal  to  twice 

*  Results  a  little  too  high.— J.  CREUSE. 

t  J.  CREUSE,  American  Chemist,  I.,  424  (1871). 


ACONITIC  ACID.  21 

that  of  the  whole  mixture,  is  added.  The  precipitate  is  washed 
on  the  filter  with  63  per  cent,  alcohol,  and  dried  at  a  moderate 
heat.  The  citrate  of  barium  contains  a  variable  quantity  of 
water,  and  is  transformed  into  sulphate  of  barium  by  transferring 
to  a  porcelain  capsule,  burning  the  filter,  and  heating  with  sul- 
phuric acid  several  times,  till  the  weight  is  constant.  3BaSO4  : 
2HSC6H507  .H20  :  :1:  0.601. 

Hager  directs  that  barium  or  calcium  citrate  (washed  with 
alcohol)  be  dried  at  120°  to  150°  and  weighed.  Ba3(C6H5O7)a  : 
2H3C6H5O7  .  H2O  :  :  1  :  0.53232. 

9.  ACONITIC  ACID.  H3C6H3O6.  A  colorless  solid,  crystal- 
lizing with  difficulty  in  warty  masses,  at  160°  C.  (320°  F.)  resolved 
into  liquid  itaconic  acid.  Soluble  in  water,  alcohol,  and  ether  ; 
its  solutions  having  a  decided  acid  reaction.  It  has  a  purely  acid 
taste. — The  aconitates  of  the  alkaline  metals,  magnesium,  and 
zinc  are  freely  soluble,  the  others  insoluble  or  sparingly  soluble, 
in  water.  Calcic  aconitate  is  soluble  in  about  10ft  parts  of 
cold  water  and  in  a  much  smaller  quantity  of  boiling  water. 
Manganous  aconitate  crystallizes  in  rose-colored  octahedrons, 
sparingly  soluble  in  water.  Argentic  aconitate  is  sparingly 
soluble  in  water,  soluble  in  alcohol  or  ether,  blackened  by 
boiling  with  water. — Free  aconitic  acid  is  precipitated  by  mer- 
curous  nitrate,  but  not  by  most  metallic  salts  until  after  neu- 
tralization. 

Aconitic  acid  is  separated  from  Monkshood  (Aconitum 
napelhts),  Larkspur  (Delphinium  consolida),  Equisetum,  Black 
Hellebore,  Yarrow  (Achillea  millefolium),  and  other  plants,  in 
which  it  exists  as  calcium  salt,  by  evaporating  the  clear  decoc- 
tion to  crystallize.  The  crystals  of  aconitate  of  calcium  are  dis- 
solved and  precipitated  by  acetate  of  lead,  and  the  lead  salt 
decomposed  by  hydrosulphuric  acid.  It  is  also  separated  from 
impurities  by  adding  (to  the  dry  mixture)  five  parts  of  absolute 
alcohol,  then  saturating  the  filtered  solution  with  hydrochloric 
acid,  and  adding  water,  when  aconitate  of  ethyl  will  rise  as  an 


22  SOLID  NON-VOLATILE  ACIDS. 

oily  layer,  colorless  and  of  aromatic  odor.      This  ether  may  be 
decomposed  by  potassa. 

Aconitic  acid  may  be  separated  from  Maleic  acid  by  the 
more  ready  crystallization  of  the  latter,  and  from  Fumaric  acid 
by  being  more  soluble  in  water. 

10.  MALIC  ACID.  H2C4H4O0.  Identified  more  especially 
by  its  deportment  \vhen  heated  (a) ;  by  the  deportment  of  its 
lead  salt  when  heated  under  water  (5),  and  of  its  calcium  salt  in 
water  and  in  alcohol  (d). — Separated  from  tartaric,  citric,  oxalic, 
and  other  acids  by  alcoholic  solubility  of  the  neutral  malate  of 
ammonium  (c)  and  by  its  reaction  with  calcium  in  water  solu- 
tions (d ) ;  from  tannic  acid,  also,  by  aqueous  solubility  of  calcic 
malate,  and  from  formic,  acetic,  benzoic  acids  by  alcoholic  inso- 
lubility of  calcic  malate  (d). — Determined  gravimetrically  as 
lead  malate  (e). 

Crystallizes  in  four-sided  or  six-sided  prisms,  deliquescent  in 
air ;  colorless,  odorless,  and  of  sour  taste ;  freely  soluble  in 
water  and  alcohol,  soluble  in  ether.  The  malates  are  mostly 
soluble  in  water,  but  insoluble  in  alcohol.  Nitric  acid  oxidizes 
malic  acid,  and  alkaline  solution  of  permanganate  is  decolorized 
by  it,  but  chromic  acid  acts  on  it  with  difficulty.  Malate  of 
silver  darkens  but  slightly  on  boiling  (Tartrate  blackens).  Con- 
centrated sulphuric  acid  darkens  malic  acid  very  slowly  after 
warming.  Hydriodic  acid  changes  it  to  succinic  acid  with  sepa- 
ration of  iodine  (the  result  being  the  same  with  Tartaric  acid). 
Sodium  amalgam  changes  malic  to  succinic  acid. 

a.  Free  malic  acid,  heated  in  a  small  retort  over  an  oil-bath 
to  175°  or  180°  C.,  evolves  vapors  of  maleic  and  fumaric  acids, 
which  crystallize  in  the  retort  and  receiver.  The  fumaric  acid 
forms  slowly  at  150°  C.,  and  mostly  crystallizes  in  the  retort,  in 
broad,  colorless,  rhombic  or  hexagonal  prisms,  which  vaporize 
without  melting  at  about  200°  C.,  and  are  soluble  in  250  parts 
of  water,  easily  soluble  in  alcohol  or  ether.  If  the  temperature 
is  suddenly  raised  to  200°,  the  maleic  acid  is  the  chief  product. 


MALIC    ACID.  23 

Maleic  acid  crystallizes  in  oblique,  rhomboidal  prisms,  which 
melt  at  130°  and  vaporize  at  about  160°,  and  are  readily  soluble 
in  water  and  in  alcohol.  The  test  for  malic  acid,  by  heating  to 
175°  or  180°,  may  be  made  in  a  test-tube,  with  a  sand-bath,  the 
sublimate  of  fumaric  and  maleic  acids  condensing  in  the  upper 
part  of  the  tube.  Malic  acid  melts  below  100°,  and  does  not 
lose  weight  at  120°  ;  at  the  temperature  of  the  test  water- vapor 
is  separated — maleic  and  fumaric  acids  both  having  the  composi- 
tion of  malic  anhydride  (C4H4O4). 

b.  Solution  of  acetate  of  lead  precipitates  malic  acid,  more 
perfectly  after  neutralizing  with  ammonia,  as  a  white  and  fre- 
quently crystalline  precipitate  which  upon  a  little  boiling  melts 
to  a  transparent,  waxy  semi-liquid  (a  characteristic  reaction,  ob- 
scured by  presence  of  other  salts).     The   precipitate    is   very 
sparingly   soluble  in  cold  water,  somewhat  soluble  in  hot  water 
(distinction  from  Citrate  and  Tartrate)  ;  soluble  in  strong  ammo- 
nia,   but   not   readily    dissolved    in    slight   excess    of   ammonia 
(distinction   from    citrate    and    tartrate)  ;    slightly  ^soluble    in 
acetic  acid. 

c.  If  the  precipitate  of  malate  of  lead  is  treated  with  excess 
of  ammonia,  dried  on  the  water  bath,  triturated  and  moistened 
with  alcoholic  ammonia,  and  then  treated  with  absolute  alcohol, 
only    the    malate    of    ammonium    dissolves    (distinction    from 
Tartaric,  Citric,  Oxalic,  and  many  other  organic  acids,  the  normal 
ammonium   salts  of  which   are    insoluble  in  absolute  alcohol). 
Also,  malic   acid  may   be  separated  from  tartaric,  oxalic,  and 
citric  acids,  in  solution,  by  adding  ammonia  in  slight  excess,  and 
then  8  or  9  volumes  of  alcohol,  which  leaves  only  the  malate  of 
ammonium  in  solution. 

d.  Solution  of  chloride  of  calcium  does  not  precipitate  malic 
acid  or  malates  in  the  cold  (distinction  from  Oxalic  and  Tartaric 
acids) ;  only  in  neutral  and  very  concentrated  solutions  is  a  pre- 
cipitate formed  on  boiling  (while  calcic  citrate  is  precipitated  in 
neutral  boiling  solutions  if  not  very  dilute).     The  addition  of 
alcohol  after  chloride  of  calcium  produces  a  white  bulky  precipi- 


24  SOLID   NON-VOLATILE  ACIDS. 

tate  of  calcic  malate  in  even  dilute  neutral  solutions  (indicative 
in  absence  of  sulphuric  and  other  acids  whose  calcium  salts  are 
less  soluble  in  alcohol  than  in  water). — Acetic,  Formic,  and 
Benzoic  acids  are  left  in  solution  and  malic  acid  precipitated  by 
addition  of  one  or  two  volumes  of  alcohol,  with  chloride  of 
calcium.  In  separation  from  Tannic  acid,  both  acids  may  be 
precipitated  by  chloride  of  calcium,  with  a  slight  excess  of 
ammonia  and  alcohol;  the  malate  is  then  washed  out  of  the 
precipitate  with  water. 

Quantitative. — e.  The  alcoholic  solution  of  malate  of  am- 
monium— prepared  as  directed  in  c — may  be  precipitated  with 
acetate  of  lead,  washed  with  alcohol,  dried  and  weighed  as  malate 
of  lead.  PbC4H4Oa  :  H2C4H4O5  :  :  1  :  0.3953. 

11.  MECONIC  ACID.  H3C7HO7.  Identified  by  its 
physical  properties  and  precipitation  by  hydrochloric  acid  (a) ; 
its  reactions  with  iron  and  other  metals  (#)  ;  and  by  its  products 
when  heated  (c).  It  is  separated  from  opium  through  formation 
of  the  calcium  salt  or  lead  salt  (d). 

a.  Meconic  acid  crystallizes  in  white  shining  scales  or  small 
rhombic   prisms,  containing    three    molecules    of  crystallization 
water,  fully  given  off  at  100°  C.     It  is  soluble  in  115  parts  of 
water  at  ordinary  temperatures,  less  soluble  in  water  acidulated 
with  hydrochloric  acid,  more  soluble  in  hot  water,  freely  soluble 
in  alcohol,  slightly  soluble  in  ether.    It  has  an  acid  and  astringent 
taste  and  a  marked  acid  reaction.    Its  salts,  having  two  atoms  of 
its  hydrogen  displaced  by  acid,  are  neutral  to  test-paper.     Except 
those  of  the  alkali  metals,  the  dimetallic  and  trimetallic  meco- 
nates  are  mostly  insoluble  in  water.     Meconates  are  nearly  all 
insoluble  in  alcohol.     They  are  but  slightly  or  not^at  all  decom- 
posed by  acetic  acid. 

Solutions  of  meconates  are  precipitated  by  hydrochloric 
acid,  as  explained  above. 

b.  Solution   of  meconic  acid  is  colored  red  by  solution  of 
ferric  chloride.     One  ten-thousandth  of  a  grain  of  the  acid  in 


ME  CONIC  ACID.  25 

one  grain  of  water  with  a  drop  of  the  reagent  acquires  a  distinct 
purplish-red  color  (WORMLEY).  The  color  is  not  readily  dis- 
charged by  addition  of  dilute  hydrochloric  acid  (distinction  from 
Acetic  acid),  or  by  solution  of  mercuric  chloride  (distinction 
from  sulphocyanic  acid). — Solution  of  acetate  of  lead  precipi- 
tates meconic  acid  or  meconates  as  the  yellowish-white  meconate 
of  lead,  Pb3(C7HO7)2,  insoluble  in  water  or  acetic  acid. — Excess 
of  baryta  water  precipitates  a  yellow  trimetallic  meconate. — 
Solution  of  nitrate  of  silver  in  excess  precipitates  free  meconic 
acid  on  boiling,  and  precipitates  meconates  directly,  as  yellow 
trimetallic  meconate ;  if  free  meconic  acid  is  in  excess,  the  preci- 
pitate is  first  the  white  dimetallic  meconate ;  both  meconates 
being  soluble  in  ammonia  and  insoluble  in  acetic  acid. — Solution 
of  chloride  of  calcium  precipitates  from  solutions  of  meconic 
acid,  and  even  from  neutral  meconates,  chiefly  the  white  mono- 
metallic meconate,  CaH4(C7HO7)2 .  2H2O,  sparingly  soluble  in 
cold  water ;  in  the  presence  of  free  ammonia,  the  less  soluble, 
yellow  dimetallic  salt,  CaH  C7HO7 .  H2O,  is  formed.  Both  preci- 
pitates are  soluble  in  about  20  parts  of  water  acidulated  with 
hydrochloric  acid. 

c.  At  120°  C.  (248°  F.)  dry  meconic  acid  is   resolved  into 
comenic  acid ;  at  above  200°  C.  the  comenic  acid  is  resolved 
into  pyrocomenic  acid  and  other  products.      The  sublimate  of 
comenic  acid  dissolves  sparingly  in  hot  water,  not  at  all  in  abso- 
lute alcohol.     It  crystallizes  in  prisms,  plates,  or  granules.     Solu- 
tion of  comenic  acid  gives  a  red  color  with  ferric  chloride,  green 
pyramidal  crystals  with  cupric  sulphate  in  concentrated  solu- 
tion, and  a    yellowish-white    granular    precipitate  with  acetate 
of  lead. 

d.  The  separation  of  meconic,  acid  from  opium  is  effected 
with  least  loss  by  precipitating  the  infusion  with  acetate  of  lead 
(leaving  the  alkaloids  as  acetates  with  some  excess  of  lead  in  the 
filtrate).     The  precipitate  is  decomposed,  in  water,  with  hydro- 
sulphuric  acid  gas,  and  the  filtrate  therefrom  is  concentrated  (and 
acidulated  with  hydrochloric  acid)  to  crystallize  the  meconic  acid. 


26  SOLID   NON-VOLATILE  ACIDS. 

The  crystals  are  purified  by  dissolving  in  hot  water  and  crystal- 
lizing in  the  cold  after  acidulation  with  hydrochloric  acid. 

The  calcium  meconate,  precipitated  in  concentrated  solution 
by  Gregory's  process  for  preparation  of  morphia,  as  by  the  Br. 
Pharmacopoeial  preparation  of  morphise  murias,  is  washed  with 
cold  water  and  pressed.  One  part  of  the  precipitate  is  dissolved 
by  digestion  in  20  parts  of  nearly  boiling  water  with  3  parts  of 
commercial  hydrochloric  acid,  and  set  aside  to  crystallize  the  acid 
meconate  of  calcium.  The  crystals  are  purified  from  color  and 
freed  from  calcium  by  repeated  solution  in  the  same  solvent,  used 
just  below  100°  C.,  and  each  time  in  a  slightly  diminished  quan- 
tity. The  acid  may  be  further  decolorized  by  neutralizing  with 
potassic  carbonate,  dissolving  in  the  least  sufficient  quantity 
of  hot  water,  draining  the  magma  of  salt  when  cold,  dissolv- 
ing again  in  hot  water  and  adding  hydrochloric  acid  to  crys- 
tallize. 

12.  DIGITALIO  ACID.     Digitaleic  acid.     Digitoleic  acid. 
— A  solid  of  a  green  color,  crystallizing  in  slender  needles,  some- 
times stellate,  having  a  bitter  taste  and  pleasant  aromatic  odor. 
It    is    sparingly    soluble    in   water,    freely   soluble    in    alcohol 
and  in  ether.     It  reddens  litmus    and   decomposes  carbonates. 
The   alkaline  digitalates  are   soluble,   forming  soapy  solutions 
with  water;    the   other  metallic    digitalates    are   insoluble    in 
water. 

Digitalic  acid  is  obtained  from  the  leaves  of  the  fox-glove 
(digitalis  purpurea)  by  exhausting  with  cold  water,  precipitating 
the  solution  with  acetate  of  lead,  decomposing  the  precipitate 
with  solution  of  carbonate  of  sodium,  and  treating  the  somewhat 
concentrated  filtered  solution  with  hydrochloric  acid,  which  pre- 
cipitates crude  digitalic  acid.  This  is  purified  by  crystallization 
from  alcohol. 

13.  TANNIC   ACIDS :  Vegetable  educts  having  an  astrin- 
gent taste  and  an  acid  effect  on  test-papers,  mostly  amorphous, 


TANNIC  ACIDS.  27 

not  volatile  or  liquefiable,  freely  soluble  in  water  and  in  alcohol, 
mostly  but  little  soluble  in  dilute  sulphuric  acid ;  forming  with 
ferric  salts  green  or  blue  colors,  and  precipitating  solutions  of 
gelatin  and  albumen  (distinctions  from  gallic  acid).  Attributed 
formulae,  C27H24O18 ;  C27H22O17 ;  C14H10O9  (SCHIFF). 

The  tannic  acids  are  further  characterized  by  forming  in  solu- 
tions of  all  the  caustic  alkalies  a  brown  color  bleached  by  oxalic 
acid,  and  in  solutions  of  alkaloids  a  white  precipitate  dissolved 
by  acetic  and  stronger  acids.  With  exceptions  hereafter  named, 
they  precipitate  solution  of  tartrate  of  antimony  and  potassium  ; 
they  precipitate  basic  acetate  of  lead,  and  form  insoluble  com- 
pounds with  many  heavy  metals.  They  all  absorb  oxygen,  espe- 
cially in  presence  of  alkalies,  and  act  as  powerful  reducing  agents 
— quickly  decolorizing  solution  of  permanganate,  and  reducing 
the  heated  alkaline  copper  solution.  Tannic  acids  are  more  per- 
manent in  alcoholic  than  in  aqueous  solutions. 

If  a  very  little  starch-paste  be  tinged  blue  by  a  slight  addition 
of  hundredth-normal  solution  of  iodine  (1  part  iodine^xlissolved 
with  potassic  iodide  in  100,000  parts  aqueous  solution),  on  adding 
a  liquid  containing  tannic  acid  the  blue  color  of  the  iodized  starch 
presently  disappears — hydriodic  acid  and  gallic  acid  being  formed. 
On  adding  a  crystal  of  potassic  nitrite  the  blue  is  restored.* 
Also,  if  a  drop  of  tannic  acid  solution  is  mixed  with  a  few  drops 
of  iodine  solution  of  the  above  strength,  and  afterward  a  drop  of 
very  dilute  alkali  be  added,  on  evaporation  to  remove  carbonic 
acid,  a  bright  red  color  wrill  appear. f  By  oxidation  the  tannic 
acids  acquire  a  dark  color,  brown,  black,  green,  or  red.  Gallotannic 
acid  with  alkalies  in  the  air  slowly  forms  tannoxylic  acid,  which 
precipitates  acetate  of  lead  solution  dark-red.  With  lime-water 
it  forms  a  white  turbidity,  becoming  green  and  darker.  Tannic 
acids  form  with  molybdate  of  ammonium  a  red  color  removed 
by  oxalic  acid. 

The  physiological  tannic  acid  (WAGNER,  1866)  or  quercitan- 

*  GRIESSMAYER  :   Ann.  Oh.  Pharm.,  clx.,  40-56. 
t  GRIESSMAYER  :  Zeitschr.  Anal.  Chem.,  x.,  43. 


28  SOLID  NON-VOLATILE  ACIDS. 

nic  acid  is  found  in  the  bark  of  the  oak,  pine,  willow,  and  beech, 
in  bablah  (acacia  fruit),  in  valonia  (cups  of  the  quercus  gegilops), 
and  in  sumac.  It  is  a  glucoside,  and  it  does  not  yield  pyrogal- 
lic  acid  by  dry  distillation.  The  pathological  tannic  acid  of 
Wagner,  or  gallotannic  acid,  is  found  in  common  or  Turkish  gall- 
nuts  and  in  Chinese  and  Japanese  gall-nuts.  It  is  a  glucoside 
(being  transformed  by  contact  of  a  ferment  or  by  sulphuric  acid 
into  gallic  acid  and  glucose),  and  in  dry  distillation  it  yields 
pyrogallic  acid. 

Ferric  salts  give  blue  to  blue-black  precipitates  with  gallo- 
tannic acid,  quercitannic  acid,  and  the  tannic  acids  of  poplar 
bark,  birch  bark,  hazel-nut,  uva  ursi  leaves,  lithrum  salicaria 
leaves,  the  bark  of  cornus  florida  and  cornus  mascula,  and  many 
other  plants.  Ferric  gallotannate  (ink)  is  bleached  by  oxalic 
acid.  On  digestion  with  nitric  acid,  a  yellowish  solution  is 
formed,  in  which  excess  of  ammonia  precipitates  ferric  hydrate. 
Ferric  salts  give  green  precipitates  with  quinotannic  acid,  mori- 
tannic  acid,  caffetannic  acid,  catechutannic  acid,  catechuic  acid, 
cephaelic  acid,  the  tannic  acids  of  the  barks  of  pines  and  fir  and 
willow,  the  rhubarb  root,  the  root  of  potentilla  tormentilla,  and 
of  numerous  other  plants.  Cephaelic  acid  with  ammonia  is 
colored  violet  to  black  by  ferric  salts. 

Gelatin  does  not  precipitate  Catechuic  acid  or  CafFe- 
tannic  acid. 

Tannic  acids  are  removed  from  solution  by  digestion  with 
oxide  of  copper,  oxide  of  zinc,  or  animal  membrane  ;  or  by  pre 
cipitation  with  solution  of  gelatin,  sulphate  of  cinchonia,  or 
acetate  of  copper. — They  are  separated  as  insoluble  lead  salts, 
according  to  the  general  method  given  under  Acetic  Acid. 

Quantitative. — The  total  tannic  acids  in  solution  are  deter- 
mined— by  the  specific  gravity  (a) ;  by  absorption  in  oxide  of 
copper  (b) ;  by  a  volumetric  solution  of  sulphate  of  cinchonia 
(c)  ;  by  a  volumetric  solution  of  tartrate  of  antimony  and 
potassium  (in  presence  of  chloride  of  ammonium  to  prevent  the 
precipitation  of  gallic  acid)  (d). 


TANNIC   ACIDS. 


a.  A  water  solution  of  gallotannic  acid&t  17.5°  C.  (63.5°  F.) 
contains  as  follows  (after  HAGER)  : 


p-c. 

SPEC.  GRAV. 

P.  C. 

SPEC.  GRAY. 

P.  C. 

SPEC.  GRAY. 

20 

1.0834 

13 

1.0530 

6 

1.0242 

19.5 

1.0803 

12.5 

1.0510 

5.5 

1.0222 

19 

1.0782 

12 

1.0489 

5 

1.0201 

18.5 

1.0761 

11.5 

1.0468 

4.5 

1.0181 

18 

1.0740 

11 

1.0447 

4 

1.0160 

17.5 

1.0719 

10.5 

1.0427 

3.5 

1.0140 

17 

1.0698 

10 

1.0406 

3 

1.0120 

16.5 

1.0677 

9.5 

1.0386 

2.5 

1.0100 

16 

1.0656 

9 

1.0365 

2 

1.0080 

15.5 

1.0635 

8.5 

1.0345 

1.5 

1.0060 

15 

1.0614 

8 

1.0324 

1 

1.0040 

14.5 

1.0593 

7.5 

1.0304 

0.5 

1.0020 

14 

1.0572 

7 

1.0283 

0 

1.0000 

13.5 

1.0551 

6.5 

1.0263 

When  other  substances  besides  tannic  acid  and  water  are 
present,  the  specific  gravity  of  the  solution  is  first  taken ;  the 
solution  is  then  deprived  of  tannic  acid  by  digestion  with  animal 
membrane.  Four  to  five  parts  of  dried  and  rasped  hide  are 
added  for  one  part  supposed  tannic  acid.  After  digestion,  the 
filtrate  and  washings  are  brought  to  the  exact  bulk  of  the  original 
solution  and  to  the  standard  temperature.  The  former  specific 
gravity  minus  the  latter,  and  plus  one,  equals  the  specific  gravity 
indicating  the  per  cent,  of  tannin.  Gallic  acid  is  not  taken  out 
by  the  membrane. — If  pectous  substances  are  present,  they  would 
also  be  precipitated  by  the  animal  membrane ;  hence  they  must 
be  removed  before  taking  the  specific  gravity  in  the  first  place. 
This  is  accomplished  by  making  an  alcoholic  extract  of  the  ori- 
ginal material,  then  evaporating  off  the  alcohol  and  substituting 
water  (HAMMER). — Instead  of  animal  membrane,  oxide  of  copper 
may  be  used  to  remove  the  tannic  acid  (and  gallic  acid),  accord- 
ing to  b. 

b.  A  weighed  quantity  of  recently  ignited  oxide  of  copper — . 
about  5  times  that  of  the  tannin — is  added  to  the  prepared  solu- 
tion ;  the  mixture  is  gently  warmed  for  an  hour  and  set  aside  for  a 
day  with  frequent  agitation,  then  filtered  and  the  copper  tannate  and 


30  SOLID  NO N- VOLATILE  ACIDS. 

oxide  washed,  dried  on  the  water-bath  and  weighed.     The  increase 
of  weight  is  the  amount  of  tannic  (and  gallic)  acid  (HAGER)  . 

c.  4.523  grams  of  good  sulphate  of  cinchonia,  with  0.5  gram 
sulphuric  acid,  and  0.1  gram  acetate  rosanilin  or  fuchsin,  are  dis- 
solved in  water  to  make  one  litre.      Each  c.c.  of  this  solution 
precipitates  0.01  gram  tannic  acid.     One  gram  of  solid  material 
is  obtained  in  clear  solution  of  about  50  c.c.  measure.     To  this 
the  standard  solution  of  cinchona  is  added,  the  color  being  thrown 
down  in  the  precipitate.     When  the  tannic  acid  is  all  precipi- 
tated, the  anilin  color  appears  in  solution.     One  gram  having 
been  taken,  each  c.c.  of  the  volumetric  solution  indicates  1  per 
cent,  of  tannic  acid.     Gallic  acid  is  not  precipitated  by  cinchonia 
(R.  WAGNER). 

d.  One  equivalent  of  tartrate  of  antimony  and   potassium, 
after  drying  on  the  water-bath   (K  SbO  C4H4O6r=325),  is  preci- 
pitated by  one  equivalent  of  tannic  acid  (C27H24O18=636)  ;  or, 
0.002555  anhydrous  tartrate  is  precipitated  by  0.005  of  the  tannin. 
Dissolving  2.555  grams  of  anhydrous  tartrate  of  antimony  and 
potassium  in  water  to  make  one  litre  of  solution,  each  c.c  of  the 
same  corresponds  to  0.005  of  tannic  acid.      The  prepared  solu- 
tion of  tannic  acid — which  may  contain  pectous  substances  with- 
out interference  with  this  method — is  treated  with  chloride  of 
ammonium,  and  the  volumetric  solution  is  added,  with  agitation, 
until  turbidity  is  no  longer  produced.     The  precipitate  separates 
well.     Gallic  acid  is  not  thrown  down  when  chloride  of  ammo- 
nium is  present  (GERLAND). 

14.  GALLIC  ACID.  C7H6O5 ;  crystallizing  with  H2O.  An 
inodorous  solid,  having  an  astringent  and  slightly  acid  taste,  an 
acid  effect  on  test-papers,  and  crystallizing  in  long,  silky  needles 
or  triclinic  prisms.  It  is  soluble  in  100  parts  of  cold  or  3  parts 
of  boiling  water,  freely  soluble  in  alcohol,  moderately  soluble  in 
ordinary  ether,  and  but  slightly  soluble  in  absolute  ether,  inso- 
luble in  chloroform  or  petroleum  naphtha.  Its  non-alkaline 
metallic  salts  are  insoluble  in  water  but  soluble  in  alcohol,  and 


GALLIC    ACID.  31 

slightly  soluble  in  officinal  ether  ;  they  are  decomposed  by  acids 
and  by  alkalies. 

Heated  to  210°-215°  C.  (410°-419°  F.),  in  absence  of  water, 
it  is  sublimed  as  pyrogallic  acid  and  carbonic  anhydride ;  at 
higher  temperatures,  other  products  are  formed. 

Gallic  acid  is  characterized  by  its  physical  properties  (as 
above  given)  ;  by  its  reactions  with  iron  salts  (a),  with  alkalies 
(5),  with  tartrate  of  antimony  and  potassa  and  with  alkaline 
arsenate  in  the  air  (c),  and  with  molybdate  of  ammonium  (d)> 
It  is  distinguished  from  the  tannic  acids  by  negative  results 
with  gelatin,  albumen,  and  starch  (e)  ;  by  not  precipitating  the 
alkaloids,  and  by  its  far  weaker  reducing  power  (f)  (distinction 
from  pyrogallic  acid  also). — Gallic  acid  is  determined,  if  free 
from  tannic  acids,  by  absorption  in  recently  ignited  oxide  of  zinc, 
according  to  method  b  in  determination  of  tannic  acid.  It  is 
separated  from  tannic  acids  and  determined  by  solution  with  car- 
bonate of  ammonium  from  the  precipitate  with  acetate  of 
copper  (g). 

a.  Ferric  salts  in  solution  give  a  deep  blue  color  with  gallic 
acid.      Ferrous  salts  give  a  blue-black  precipitate   (distinction 
from  gallotannic  acid). 

b.  Alkaline  solutions  of  gallic  acid  turn  yellow  to  brown  and 
black  in  the  air,  from  absorption  of  oxygen  and  formation  of  tan- 
nomelanic  acid,  greatly  accelerated  by  boiling.    The  latter  acid,  on 
neutralizing  with  acetic  acid,  precipitates  acetate  of  lead,  black. 

Solution  of  lime  with  gallic  acid,  forms  a  white  turbidity, 
changing  to  blue  and  then  to  green. 

c.  Tartrate  of  antimony  and  potassium  is  precipitated  white 
in  very  dilute  solution. 

A  faintly  alkaline  solution  of  arsenate  of  potassium  or  sodium, 
with  gallic  acid,  exposed  to  the  air,  soon  develops  an  intense 
green  color,  commencing  at  the  surface.  Dilute  acids  change  the 
green  to  purple-red  and  a  careful  neutralization  with  alkalies 
restores  the  green  color,  but  it  is  destroyed  by  excess  of  alkali.* 

*  PROCTOR  :  Jour.  Chem.  Soc.,  1874,  p.  509. 


32  SOLID   NON- VOLATILE  ACIDS. 

d.  Molybdate  of  ammonium  reacts  as  with  tannic  acid. 

e.  Gallic  acid  does  not  precipitate  gelatin,  albumen,  or  starch- 
paste,  but  it  forms  a  precipitate  with  a  mixture  of  gum-arabic 
and  gelatin. 

f.  Gallic  acid  does  not  reduce  alkaline  copper  solution,  but 
reduces  salts  of  gold  and  silver,  and  quickly  decolorizes  perman- 
ganate solution. 

Quantitative. — g.  The  prepared  solution  is  fully  preci- 
pitated with  a  filtered  solution  of  cupric  acetate ;  the  precipitate 
washed  and  then  exhausted  with  cold  solution  of  carbonate  of 
ammonium.  The  last  solution,  containing  all  the  gallate  of  cop- 
per with  a  very  little  tannate,  is  evaporated  to  dryness,  the 
residue  moistened  with  nitric  acid,  ignited,  and  weighed  as  oxide 
of  copper.  This  weight  multiplied  by  0.9  gives  the  quantity  of 
gallic  acid  (the  full  ratio  being  0.9126,  but  allowance  is  made  for 
solution  of  a  little  tannate  by  the  carbonate  of  ammonium. 
The  ratio  between  oxide  of  copper  and  tannic  acid  is  1.304). 
(Method -of  FLECK  modified  by  SACKUR  and  WOLF.) 

15.  PYROG-ALUC  ACID.  C6H6OS,  Pyrogalline.  Pyro- 
gallol. — Characterized  by  its  physical  properties  (a) ;  its 
peculiar  avidity  for  oxygen  (6) ;  its  reactions  with  alkalies,  lime, 
iron,  copper,  etc.  (c).  It  is  distinguished  from  tannic  acid  by 
not  precipitating  gelatin  or  moderately  dilute  tartrate  of  anti- 
mony and  potassium  or  cinchonia,  and  by  its  different  reactions 
with  both  ferrous  and  ferric  salts  :  from  gallic  acid  b;y  its  greater 
solubility  in  cold  water  and  its  far  greater  reducing  power  (b). 
It  may  be  determined  gravimetrically  as  a  lead  precipitate  (d), 
and  volumetrically  by  permanganate. 

a.  Pyrogallic  acid  crystallizes  in  long  prismatic  plates  or 
needles,  of  a  white  or  yellowish-white  color,  and  an  acid  and  very 
bitter  taste.  At  115°  C.  (239°  F.)  it  melts,  and  at  about210°  C. 
(410°  F.)  it  sublimes  with  partial  decomposition  and  formation  of 
metagallic  acid.  It  is  soluble  in  three  parts  cold  water,  freely 
soluble  in  alcohol  and  in  ether,  not  soluble  in  absolute  chloroform. 


PrROOALLIC  ACID.  33 

f    " ' 

b.  It  is  permanent  in  dry  air  free  from   ammonia,  but   in 
moist  or   ammoniacal    air    it   gradually   darkens,  and   in  water 
solution  it  turns  brown  to  black,  sooner  if  boiled,  still  mor-e^ 
rapidly   in  presence   of  alkalies,   absorption  of  oxygen  taking 
place    to   an    extent   proportional    to   the    coloration,   which   is 
destroyed  by  oxalic  acid.     It  quickly  reduces  the  alkaline  copper 
solution ;  also  salts  of  the  noble  metals,  and  reduces  acid  solu- 
tion of  permanganate  with  evolution  of  carbonic  anhydride. 

c.  With  lime  solution,  a  purple-red  color  at  first  appears, 
afterward  the  brown  color  formed  by  alkalies  as  mentioned  in  b. 
With  ferrous  salts  a  blue  color  is  formed;  with  ferric  salts  a  red 
solution,  brown  when  heated.     Acetate  of  copper  gives  a  brown- 
green  precipitate ;    acetate  of  lead  a  white,  curdy  precipitate ; 
both  soluble  in  acetic  acid. 

Quantitative. — d.  The  alcoholic  solution  of  pyrogallic  acid 
is  precipitated  with  excess  of  alcoholic  solution  of  acetate  of  lead  ; 
the  precipitate  washed  quickly  with  alcohol,  dried  by  water-bath 
and  weighed.  Pb(C6H5O3)3  :  2C6H6O3  :  :  457  :  252  :  :  1  : 
0,55142, 

16.  QUIWOTANNIC    ACID.     Cinchotannic   acid.     Kino- 
tannic  acid. — See  Tannic  acids  (13)   for  appearance,  taste,  solu- 
bilities, and  reactions  with  alkalies  and  with  iron  salts.     It  pre- 
cipitates tartrate  of  antimony  and  potassium  only  in  concentrated 
solutions.     In  oxidation  with  alkalies  it  forms  a  red-brown  color, 
due  to  cinchona-red,  which  dissolves  in  alkalies  and  in  acetic  acid, 
but  not  in  water.     Concentrated  sulphuric  acid  changes  quino- 
tannic   acid   to    cinchona-red   and   glucose.     In  dry  distillation, 
phenic  acid  is  formed,  recognized  by  the  odor.    Quinotannic  acid 
is  removed  from  solution  by  acetate  of  lead,  and  from  its  lead 
precipitate   by  hydrosulphuric  acid.     For  separation  from  Cin- 
chona bark,  see  under  Quinic  Acid,  d. 

17.  CATECHUTANMIC  ACID.     Has   the   properties    of 
tannic  acids  in  general,  giving  a  grayish-green  precipitate  with 


34  SOLID  NON-VOLATILE  ACIDS. 

ferric  salts,  and  distinguished  by  not  precipitating  tartrate  of 
antimony  and  potassium.  It  softens  when  heated,  and  by  dry 
distillation  yields  an  empyreumatic  oil.  The  product  of  its 
atmospheric  oxidation  in  water  is  red. 

Catechutannic  acid  is  separated  from  Catechu  as  follows : 
The  aqueous  infusion  of  catechu  is  heated  with  dilute  sulphuric 
acid  and  filtered ;  the  filtrate  treated  with  concentrated  sulphuric 
acid  to  precipitate  the  acid  sought ;  the  precipitate  is  washed  on 
a  filter  with  dilute  sulphuric  acid  and  pressed  between  paper.  It 
may  then  be  dissolved  in  water ;  the  solution  treated  with  car- 
bonate of  lead  and  filtered ;  the  filtrate  evaporated  in  vacuo.  It 
may  be  farther  purified  by  dissolving  in  alcoholic  ether  and 
evaporating  off'  the  solvent. 

18.  CATECHUIC  AGED.  Catechucic  acid.  Catechin. 
Tanningenic  acid. — A  white,  tasteless  powder,  or  in  fine,  silky 
needles,  melting  at  217°  C.  (423°  F.),  and  in  dry  distillation 
yielding  an  empyreumatic  oil.  Very  slightly  soluble  in  cold 
water,  soluble  in  three  parts  boiling  water,  moderately  soluble  in 
alcohol,  sparingly  soluble  in  ether.  With  alkalies  and  metallic 
salts,  and  as  a  reducing  agent,  it  gives  the  reactions  of  the  (iron- 
green)  Tannic  Acids,  from  which  it  is  distinguished  by  not  giving 
precipitates  with  tartrate  of  antimony  and  potassium  or  with 
alkaloids,  or  with  gelatin  (the  last-named  being  a  distinction 
from  catechutannic  acid).  With  strong  sulphuric  acid  it  forms 
a  deep  purple  liquid. 

Catechuic  acid  may  be  separated  from  catechutannic  acid 
and  the  other  constituents  of  catechu  by  its  sparing  solubility 
in  cold  and  ready  solubility  in  hot  water.  Bengal  catechu  is 
digested  twenty-four  hours  in  cold  water,  and  the  (slightly 
washed)  residue  is  then  exhausted -with  boiling  water.  When 
the  solution  cools,  a  yellow  deposit  of  catechuic  acid  appears. 
This  is  washed  in  cold  water.  It  may  be  decolorized  by  hot 
filtration  through  animal  charcoal.  It  is  dried  on  bibulous  paper 
by  aid  of  the  air-pump. 


TANNIC  ACIDS.  35 

19.  MORINTAKNTC     ACID.      C13H10O6.      Capable    of 
crystallization ;  yellow,  with  great  tinctorial    power,  and  of  an 
astringent,  sweetish  taste.     Melts  at  200°  C.,  and  at  higher  tem- 
peratures distils  phenic  acid.     In  reactions  with  alkalies,  oxidiz- 
ing agents,  gelatin,  tartrate   of  antimony  and   potassium,  iron 
salts,  etc.,  it  behaves  like  other  Tannic  Acids  (13).     With  ferric 
salts  it  gives  a  greenish  precipitate  ;  with  acetate  of  lead  a  yellow 
precipitate ;  with  sulphate  of  copper  a  yellowish-brown  precipi- 
tate ;  with  stannous  chloride  a  yellowish-red  precipitate. 

It  is  separated  from  Fustic  by  spontaneous  deposition  from 
the  concentrated  decoction. 

20.  CAFFETANNIC  ACID.     Caffeotannic  acid.     Has  in 
general  the  physical  properties  of  the  Tannic  Acids,  but  is  not 
incapable  of  crystallization.     It   melts    when   heated,  and  then 
gives  the  odor  of  roasted   coffee,  and  in  dry  distillation  yields 
oxy phenic  acid  as  an  oil  which  solidifies  in  the  cold. 

With  fixed  alkalies  in  solution  it  turns  yellow  to  reddish-yel- 
low, by  oxidation;  with  ammonia,  forms  a  green  color,  due  to 
viridic  acid,  which,  when  neutralized,  gives  with  acetate  of  lead  a 
blue  precipitate.  Warmed  with  concentrated  sulphuric  acid,  it 
dissolves  with  a  blood-red  color.  Distilled  with  dilute  sulphuric 
acid  and  binoxide  of  manganese,  it  evolves  quinone — a  pungent 
and  irritating  vapor,  condensing  to  a  golden-yellow  to  dingy- 
yellow,  crystallizable  substance,  heavier  than  water,  in  which  it 
is  but  slightly  soluble  wThen  cold. 

Caffetannic  acid  gives  the  green  color  with  ferric  salts.  It 
reduces  nitrate  of  silver,  in  the  specular  form,  when  heated.  It 
is  distinguished  from  the  larger  number  of  Tannic  Acids  by  not 
producing  precipitates  with  tartrate  of  antimony  and  potassium 
or  with  gelatin,  but  it  precipitates  cinchonia  and  quinia  (distinc- 
tion from  Catechuic  acid).  It  gives  a  yellow  precipitate  with 
barium  salts. 

By  gradual  addition  of  acetate  of  lead,  in  decoction  of  coffee, 
it  is  precipitated  next  after  (the  very  little)  citric  acid.  Decom- 


36  SOLID   NON-VOLATILE  ACIDS. 

posing  the  precipitate  with  hydrosulphuric  acid,  and  evaporating 
the  filtrate,  it  is  obtained  in  impure,  yellowish  mass. 

21.  BOHEIC  ACID.     C7H10O6.    Boheatannic  Acid.    Amor- 
phous, pale-yellow  solid,  caking  by  exposure  to  the  air,  melting 
at  100°  C.  to  a  waxy  mass,  very  soluble  in  water  and   alcohol. 
Both  aqueous  and  alcoholic  solutions  gradually  decompose  by 
evaporation   in   the   air.     It   colors    ferric   salts   brown.     With 
"baryta,    in    alcoholic   solution,    it   forms    a   yellow   precipitate, 
BaC7H8O6  .  H2O.     With  acetate  of  lead,  in  alcoholic  solution, 
it  forms  a  grayish-white  precipitate,  PbC7H8O6  .  H2O,  which  can 
be  washed  with  alcohol  and  dried  at  100°  C. 

It  is  separated  from  the  quercitannic  acid,  in  Hack  tea,  by 
precipitating  the  latter  with  acetate  of  lead  in  the  boiling  decoc- 
tion, filtering ;  after  twenty-four  hours  filtering  again,  and  neu- 
tralizing the  clear  solution  with  ammonia,  when  the  yellow  basic 
salt  is  precipitated,  PbO.PbC7H8O6.  The  latter  may  be 
decomposed  in  alcohol  by  hydrosulphuric  acid,  and  the  filtrate 
concentrated  in  vacuum  or  over  oil  of  vitriol. 

22.  QUTN1C    ACID.     C7H12O6.     Kinic    acid. — Identified 
by  its  physical  properties  and  reactions  (a)  ;  by  its  generation 
of  quinone    (#) ;    by    its   reactions   with   a   few   metals   (c). — 
Separated  from  cinchona  bark,  by  crystallization  from  a  solution 
freed  from  quinovic  acid  (d) ;  from  cinchona  bark,  coffee,  or  bil- 
berry, by  precipitating  its  calcium  salt  from  a  sufficiently  purified 
solution  by  adding  alcohol  (e)  ;  from  substances  forming  insoluble 
compounds  with  neutral  acetate  of  lead  by  the  solubility  of  its 
normal    lead    salt. — Determined    gravimetrically    as    calcium 
salt  (c). 

a.  Colorless,  monoclinic  prisms  or  prismatic  tablets,  melting 
at  161°  C.  (322°  F.),  at  higher  temperatures  evolving  combus- 
tible gas,  phenic  acid,  hydroquinone,  etc.  It  is  freely  soluble  in 
water,  slightly  soluble  in  alcohol,  nearly  insoluble  in  ether.  Its 
solutions  have  a  sour  taste  and  redden  litmus.  It  is  deliquescent. 


QUINIC    ACID.  37 

b.  Distilled   with    moderately    dilute    sulphuric    acid    and 
binoxide  of  manganese,  it  yields  an  abundant  yellow  crystalline 
sublimate  of  quinone,  recognized  in  very  small  quantities  by  its 
irritating  odor,   exciting    tears.     Farther,    aqueous    solution    of 
Quinone   is  colored   brown  by  ammonia,  and  yellow-green  by 
chlorine  water ;  it  stains  the  skin  brown. 

c.  Quinic  acid  decomposes  carbonates.     Its  metallic  salts  are 
soluble  in  water,  except  the  basic  quinate  of  lead,  but  are  insolu- 
ble in  alcohol.     It  prevents  the  precipitation  of  many  metallic 
oxides  by  alkalies.     Quinate  of  silver  is  white,  and   bears  the 
heat  of  the   water-bath.     The  quinate  of  calcium  crystallizes 
well   from  water  solution    as  Ca(C7H11O6),  .  5H2O,  which  loses 
all  its  water  of  crystallization  at  120°  C.  (248°  F.)     Or,  it  may 
be    precipitated    from    solution  of  alkaline  quinates   by  adding 
chloride  of  calcium,  ammonia,  and   alcohol.     The  basic  quinate 
of  lead  is  precipitated  by  adding,  to  solution  of  alkaline  quinate, 
basic  acetate  of  lead,  or  normal  acetate  of  lead  with  ammonia. 
It  is  somewhat  soluble  in  solution  of  basic  acetate  of  lead.     It 
is  variable  and  instable  in  composition. 

d.  The  aqueous  solution  obtained  by  macerating  cinchona 
bark  two  or  three  days  (and  from  which  the  alkaloids  may  have 
been  removed  by  acidulating  with  hydrochloric  acid  and  then 
adding  an  excess  of  soda  and,  after  a  few  hours,   filtering)   is 
treated  with  solution  of  acetate  of  lead  to  precipitate  the  quino- 
vic  and  quinotannic  acids,  and  filtered.    The  filtrate  is  evaporated 
to  a  syrupy  consistence,  to  crystallize  the  quinic  acid. 

If  it  be  desired  to  separate  the  Quinovic  acid,  the  solution  of 
acetate  of  lead  (as  above)  is  not  added  to  complete  precipitation, 
and  the  precipitated  quinovate  of  lead  is  decomposed,  in  water, 
by  adding  very  dilute  sulphuric  acid,  drop  by  drop,  with  great 
care,  to  avoid  excess.  The  precipitate  being  removed,  the  filtrate 
is  concentrated  for  crystallization  of  the  quinovic  acid. 

If  the  Quinotannic  acid  is  to  be  obtained,  the  precipitation  by 
acetate  of  lead  is  left  incomplete,  as  directed  next  above,  and  the 
filtrate  concentrated  as  previously  directed  for  quinic  acid. 


38  SOLID   NON-VOLATILE  ACIDS. 

With  the  crystals  of  quinic  acid  there  will  now  finally  deposit 
amorphous  or  oily  quinotannic  acid.  This  may  be  separated  by 
washing  with  ether ;  on  evaporation  of  the  ether  the  quinotannic 
acid  is  obtained.  [Thesis  of  R.  M.  COTTON,  Univ.  of  Mich.,  1874.] 

e.  After  precipitating  the  alkaloids  from  decoction  of  cin- 
chona bark  with  lime,  according  to  the  United  States  Pharma- 
copoeial  preparation  of  quinise  sulphas,  the  filtrate  is  concentrated 
to  a  small  bulk,  filtered  if  necessary,  and  then  alcohol  is  added 
to  precipitate  quinate  of  calcium.  Or,  the  filtrate  is  concentrated 
to  a  soft  solid,  washed  repeatedly  with  alcohol,  and  dissolved  in 
enough  water  to  allow  the  quinate  of  calcium  to  crystallize. 

Fresh  bilberry  plant  (vaccinium  myrtillus),  collected  in 
May,  is  boiled  with  water  and  lime ;  the  solution  is  evaporated, 
and  alcohol  added  to  precipitate  the  quinate  of  calcium,  which 
requires  purification  by  recrystallization  from  water. 

Thoroughly  dried  or  moderately  roasted  coffee  beans,  coarsely 
powdered,  are  exhausted  by  boiling  with  water ;  the  decoction, 
mixed  with  milk  of  lime,  is  concentrated,  filtered,  evaporated  on 
a  water-bath  to  a  syrup,  and  precipitated  with  alcohol  as  above. 

The  quinate  of  calcium  obtained  from  any  of  the  above 
sources  may  be  purified  from  tannic  acids  and  some  coloring 
matters  by  adding  solution  of  neutral  acetate  of  lead  to  the 
aqueous  solution  of  quinate  of  calcium,  filtering  put  the  lead 
precipitate,  and  removing  the  excess  of  lead  from  the  filtrate  by 
hydrosulphuric  acid,  when  the  last  filtrate  may  be  concentrated 
to  crystallize.  Quinic  acid  may  be  obtained  from  quinate  of 
calcium  by  precipitating  the  aqueous  solution  of  the  latter  by 
basic  acetate  of  lead,  and  removing  the  lead  from  the  precipitate 
by  hydrosulphuric  acid. 


23.  QUINOVIC  ACID.  C30H48O8.  Kinovic  Acid. 
Quinovin  or  Kinovin.  Quinova  bitter  or  Kinova  bitter. — An 
amorphous  solid,  having  a  very  bitter  taste,  nearly  insoluble  in 
svater,  very  soluble  in  alcohol,  slightly  soluble  in  ether,  soluble 
in  chloroform.  (According  to  DE  VRII,  chloroform  dissolves 


GENTIANIC    ACID.  39 

from  "quinova  bitter"  a  portion  which  he  designates  as 
"  quinovin,"  leaving  "  quinovic  acid  "  insoluble  in  that  menstruum 
and  little  soluble  in  alcohol.)  Dry  hydrochloric  acid  gas,  acting 
on  a  strong  alcoholic  solution  of  quinovic  acid,  transforms  the 
latter  into  an  acid  and  a  sugar.  The  new  acid  has  very  nearly 
the  same  solubilities  as  the  original  acid,  but  a  different  compo- 
sition (C24H38O4),  and  forms  definite  salts  with  metals. 

Quinovic  acid  forms  a  soluble  calcium  salt,  and  hence  it  is 
dissolved  from  cinchona  bark  by  boiling  with  milk  of  lime. 
From  the  solution,  sufficiently  concentrated,  hydrochloric  acid 
separates  the  quinovic  acid,  insoluble  in  water.  It  may  be 
purified  by  crystallization  from  alcohol,  or  by  repeated  precipita- 
tion from  alcohol  by  water.  For  the  separation  of  quinovic, 
quinic,  and  quinotannic  acids,  each  from  the  same  portion  of 
bark,  see-  Quinic  Acid,  d.  In  the  manufacture  of  cinchona  alka- 
loids, the  acidulation  of  the  water  by  which  the  decoction  is 
made  interferes  with  the  solution  of  quinovic  acid,  which  may  be 
at  least  partly  left  in  the  residue. 

24.  COLUMBIC    ACID.     C42H46O13.     Colombic  acid.— An 
amorphous  solid,  precipitated  in  white  flakes,  left  as  a  yellowish, 
varnish-like  residue  on  evaporation  of  its  solutions.    It  is  soluble 
in  alcohol,  nearly  insoluble  in  water  or  ether,  its  solution  being 
markedly  acid.     It  is  precipitated  by  neutral  acetate  of  lead,  as 
(PbO)3(C42H44O12)2  when    dried  at  130°  C.     Acetate  of  copper 
does  not  precipitate  it. 

In  columbo  root,  columbic  acid  probably  exists  in  combination  , 
with  berberina  and  perhaps  also  with  inorganic  bases.     It  can  be 
separated  by  exhausting  alcoholic  extract  of  columbo  with  water 
or  lime-water,  and  precipitating  with  hydrochloric  acid. 

25.  GENTIANIO  ACID.     C14H10O5.     Gentisic  acid.     Gen- 
tianin.     Gentisin. — Light-yellow,  tasteless,  solid,  crystallizing  in 
slender  needles,  not  decomposed  at  200°  C.,  but  carbonizing  with 
partial  sublimation  at  300°  to  400°  C.     It  is  soluble  in  36  parts 


40  SOLID   N ON- VOLATILE  ACIDS. 

water  at  ordinary  temperature,  readily  soluble  in  alcohol,  and 
moderately  so  in  ether.  Its  solutions  are  neutral  to  litmus.  It 
dissolves  in  aqueous  alkalies  with  a  golden-yellow  color.  Strong 
sulphuric  acid  dissolves  it  yellow.  Nitric  acid,  of  specific  gravity 
1.42,  and  colorless,  dissolves  it  green;  on  adding  water,  a  green 
powder,  dinitrogentianic  acid,  is  precipitated.  This,  on  addition 
of  alkalies,  assumes  a  fine  cherry-color.  Chlorine  forms  a  yellow 
precipitate  in  alcoholic  solution  of  gentianic  acid.  The  barium 
salt,  Ba  C14H8O5  .  H2O,  is  an  orange-colored  precipitate.  The 
lead  salt  is  insoluble. 

Gentianic  acid  is  separated  from  gentian  root  as  follows: 
The  powdered  root  is  exhausted  of  gentian-bitter  by  cold  water ; 
then  pressed,  dried,  and  exhausted  with  strong  alcohol,  and  the 
alcoholic  solution  evaporated  nearly  to  dryness.  The  residue  is 
washed  with  a  little  ether  to  remove  fat,  and  repeatedly  crystallized 
from  alcohol  to  separate  from  resin. 

26.  CAEMLN1C  ACID.  C9H20O6.  Carmine. — A  purple 
amorphous  solid,  fusible  but  not  decomposed  at  136°  C. ;  soluble 
in  all  proportions  in  water  and  alcohol,  and  in  sulphuric  and 
hydrochloric  acids  without  alteration,  the  solutions  having  a 
bright  purple-red  color.  Ether  does  not  dissolve  it. — In  alco- 
holic solution  it  precipitates  alcoholic  potassa  red  changing  to 
dark  violet,  and  forms  red  precipitates  with  acetates  of  ]ead, 
zinc,  copper,  and  silver.  It  is  turned  blue  by  sulphate  of  alumi- 
num, and  yellow  by  stannous  chloride. — Carminic  acid  is  a 
glucoside,  boiling  dilute  mineral  acids  transforming  it  into 
carmine-red and  sugar.  Carmine-red  in  mass  is  purple-red  with 
a  green  reflection,  soluble  in  water  and  in  alcohol  with  red  color, 
not  soluble  in  ether. 

Carminic  acid  is  separated  from  Cochineal  by  exhaustion 
with  boiling  water ;  the  solution  precipitated  by  adding  slightly 
acidulated  subacetate  of  lead  short  of  excess,  the  precipitate 
washed  with  water  till  the  washings  give  no  precipitate  with 
mercuric  chloride,  then  decomposed  by  hydrosulphuric  acid  and 


GAMBOGIC    ACID.  41 

filtered.     The  filtrate  is  evaporated  and  dried  on  the  water-bath, 
and  the  residue  extracted  with  alcohol. 

27.  CHRYSOPHANTC     ACID.       Chrysophane.       Rheic 
Acid. — A  pale  yellow  or  orange-yellow  solid,  crystallizing  in  six- 
sided  tables  or  moss-like  aggregates  of  scales,  subliming  with 
partial  decomposition  when  heated. — Sparingly  soluble  in  cold 
water,  soluble  in  1,125   parts  of  86  per  cent,  alcohol  at  30°  C. 
(86°  F.),  or  224  parts  of  the  same  alcohol  boiling,  soluble  in 
ether,  benzole,  and  turpentine  oil,  the  solutions  having  a  yellow 
color. — It  dissolves  in  aqueous  alkalies  with  a  very  deep  purple 
color,  recognized  in  very  dilute   solution;  the  potassa  solution 
upon  evaporation  deposits  violet  to  blue  flocks,  which  dissolve  in 
water  to  a  red  solution. — It  does  not  form  stable  salts.     In  alco- 
holic solution  with  alcoholic  subacetate  of  lead  it  forms  a  reddish- 
white  precipitate,  becoming  rose-red  when  boiled  with  water.    In 
ammomacal  solution  it  is  precipitated  filac  by  neutral  acetate  of 
lead,  and  rose-color  by  alum. — Strong  sulphuric  acid  dissolves  it 
unchanged;  strong  nitric  acid  converts  it  into  a  red  substance, 
containing  chrysammic  acid  (produced  from  Aloes  by  nitric  acid) . 

Chrysophanic  acid  is  separated  from  Rhubarb  by  exhausting 
the  powdered  root  with  alcoholic  ammonia,  precipitating  with 
subacetate  of  lead  and  decomposing  the  lead  compound  by 
hydrosulphuric  acid.  From  the  Wall  Lichen  (Parmdia 
parietina),  the  alkaline  solution  obtained  as  above  is  precipitated 
by  acetic  acid,  the  precipitate  washed  with  water,  redissolved  in 
alkali  and  reprecipitated  by  (hydrochloric)  acid.  From  the 
Rumex,  an  ethereal  extract  is  obtained,  and  repeatedly  dissolved 
in  alcohol  and  precipitated  by  water.  A  method  of  purification 
is  to  dissolve  in  boiling  absolute  alcohol  and  crystallize. 

28.  GAMBOGIO    ACID.     A   resinous    solid,   hyacinth-red 
in   mass,   yellow    in   powder.     Insoluble   in   water,    soluble   in 
alcohol,    ether,    chloroform,  bisulphide  of  carbon — its  solutions 
showing  the  yellow  color  when  very  dilute,  and  having  a  strong 


42  SOLID    VOLATILE   ACIDS. 

acid  reaction.  It  dissolves  in  the  aqueous  alkalies,  with  red 
color,  and  in  solutions  of  fixed  alkaline  carbonates  with  expulsion 
of  the  carbonic  anhydride.  From  alkaline  solutions  it  is  preci- 
pitated yellow  by  acids. — The  solution  of  gambogiate  of  ammo- 
nia forms  with  barium  salts  a  red  precipitate ;  with  zinc  salts, 
yellow ;  lead  salts,  reddish-yellow ;  silver  salts,  brownish-yellow ; 
and  copper  salts,  brown  precipitates. — It  is  bleached  and  decom- 
posed by  chlorine,  and  decomposed  with  formation  of  nitrophenic 
acid  by  nitric  acid.  It  is  dissolved  with  red  color  by  cold  con- 
centrated sulphuric  acid;  addition  of  water  precipitating  it 
unchanged. 

29.  SANTAUC  ACID.  Santalin. — A  fine  red,  tasteless, 
and  odorless  crystallizable  solid,  melting  at  104°  C.  Insoluble 
in  water,  very  soluble  in  alcohol,  soluble  in  ether — the  solutions 
having  a  blood-red  color  and  acid  reaction.  Soluble  in  aqueous 
potassa,  or  ammonia,  forming  violet  solutions,  which  precipitate 
alkaline  earths. — The  alcoholic  solution  precipitates  lead  salts, 
but  not  salts  of  barium,  silver,  or  copper.  The  lead  and  barium 
salts  are  violet. 

Santalic  acid  is  separated  from  Sandal- wood  (red  saunders) 
by  obtaining,  first,  an  ethereal  extract,  then  from  this  an  alcoholic 
extract,  which  is  washed  with  water,  dissolved  again  in  alcohol, 
and  precipitated  therefrom  by  alcoholic  solution  of  acetate  of 
lead.  The  lead  compound  is  washed  by  alcohol,  then  decom- 
posed in  alcohol  with  dilute  sulphuric  acid. 


SOLID    VOLATILE    ACIDS. 

30.  BENZOIC  ACID.  HC7H5O2.  Identified  by  its  phy- 
sical properties,  especially  in  sublimation  (a) ;  by  its  oxidation 
to  nitrobenzole  (&),  and  its  deoxidation  to  bitter  almond  oil  (c) ; 
by  its  reactions  with  metallic  salts  (d). — Distinguished  from 


BENZOIC   ACID,  43 

Cinnamic  acid  by  the  action  of  permanganate  upon  the  latter 
(see  31,  1) ;  from  Hippuric  acid  by  distillation  with  potassa; 
from  Salicylic  acid  by  the  color  of  its  ferric  salt  (d). — Separated 
from  non-volatile  and  highly  volatile  substances  by  sublimation 
(a)  ;  from  Succinic  and  many  other  acids  by  the  alcohol  solubility 
of  its  barium  salt  (d) ;  from  Succinic  and  Hippuric  acids  by  its 
solubility  and  extraction  from  water  solutions  by  chloroform  or 
ether  (c). — Gravimetrically  determined  as  lead  salt  (e). 

a.  A  white  solid,  crystallizing  in  lustrous  scales  or  friable 
needles ;  odorless  when  pure,  but  frequently  found  having  odor 
of  benzoin,  and  rarely  a  urinous  odor,  of  an  acid  and  warm  taste, 
and  a  strongly  acid  reaction.     It  is  soluble  in  200  parts  of  water 
at  15°  C.  (59°  F.),  in  20  parts   of  boiling  water,  in  3  parts  of 
cold  alcohol,  in  25  parts  of  ether,  in  7   parts  of  chloroform,  and 
readily    soluble   in   bisulphide    of    carbon,    benzole,    petroleum 
naphtha,  and  in  fixed  and  volatile  oils.     Most  of  the  benzoates 
are  soluble  in  water,  and  many  of  them  are  soluble  in  alcohol. 

Hydrochloric  acid  precipitates  benzoic  acid  from  solutions 
of  benzoates,  excess  of  the  reagent  not  affecting  the  water  solu- 
bility of  benzoic  acid  as  already  given.  Sulphuric  acid  dissolves 
benzoic  acid.  Benzoic  acid  decomposes  carbonates. 

Benzoic  acid  melts  at  121°  C.  (250°  F.),  and  sublimes  at 
240°  to  250°  C.  (464°  to  482°  F.)  The  vapors  cause  a  sense  of 
irritation  in  the  throat  and  coughing.  When  slowly  condensed, 
the  sublimate  is  crystalline  in  minute  needles.  Benzoates  heated 
with  phosphoric  acid  evolve  benzoic  acid. — When  mixed  with 
3  parts  slaked  lime  and  heated  gradually  in  a  retort,  benzole 
(119)  is  distilled. 

b.  If  benzoic  acid  is  boiled  with  concentrated  nitric  acid,  the 
mixture  evaporated  to  a  small  bulk,  and  then  strongly  heated  in 
a  test-tube,  nitrobenzole  (120)  is  evolved,  and  will  be  recognized 
by  its  odor  of  bitter  almond  oil. 

c.  When  benzoic  acid,  dissolved  or  suspended  in  water,  is 
warmed  with  a  slip  of  metallic   magnesium,   and  very  slightly 
acidulated   with   sulphuric   acid,   so    that   hydrogen  is  Devolved, 


44  SOLID    VOLATILE  ACIDS. 

bitter  almond  oil  (benzoyl  hydride,  C7H,OH)  is  produced,  and 
recognized  by  its  odor. 

d.  Basic  ferric  chloride  solution  precipitates  benzoates  almost 
completely,  as  a  flesh-colored  basic  benzoate  (ferric  Salicylate  is 
blue  violet). — Acetate  of  lead  and  nitrate  of  silver  give  precipi- 
tates in  solutions  not  too  dilute. — Ammoniacal  chloride  of 
barium  with  alcohol  gives  no  precipitate  (distinction  and  separa- 
tion from  Succinic  and  many  other  acids) .  Magnesium  benzoate 
is  also  soluble  in  alcohol  (Succinate  insoluble  in  alcohol). 

Quantitative. — e.  Benzoate  of  lead,  precipitated  from  neutral 
benzoate  by  acetate  of  lead,  washed  with  cold  water  or  alcohol 
acidulated  with  one-half  per  cent,  of  acetic  acid,  and  dried  at 
100°  C.,  may  be  weighed  for  determination  of  benzoic  acid : 
Pb(C7H6O2)2  :  2HC7H503  :  :  1  :  0.54343. 

31.  CINNAMIC  ACID.  HC9H7O2.  Characterized  by  its 
physical  properties  and  reactions  in  the  dry  way  (a) ;  its  reac- 
tions with  oxidizing  agents  (b) ;  its  reactions  with  metallic 
salts  (c). — Distinguished  from  benzoic  acid  by  action  with 
oxidizing  agents  (£),  by  the  color  of  its  ferric  salt  and  by  its 
precipitate  with  manganous  salts  (c) . — Separated  from  non-vola- 
tile substances  by  sublimation  (a) ;  from  substances  soluble  in 
water  and  in  dilute  acid  by  precipitation  of  cinnamates  by  acids 
(a) ;  from  substances  insoluble  in  ether  by  the  action  of  that 
solvent ;  from  benzoic  acid  by  manganous  precipitation  (c) . 

a.  A  colorless  solid,  crystallizing  (from  vapor  or  solution)  in 
monoclinic  prisms  or  laminae,  melting  at  129°  C.  (264°  F.), 
vaporizing  at  about  300°  C.  (572°  F.)  It  is  very  sparingly 
soluble  in  cold,  moderately  soluble  in  boiling  water,  freely 
soluble  in  alcohol  and  in  ether.  The  cinnamates  of  the  alkali 
metals  are  soluble  in  water,  those  of  the  alkaline  earthy  metals 
sparingly  soluble,  the  other  cinnamates  mostly  insoluble,  the 
silver  salt  nearly  insoluble. 

It  is  precipitated  by  water  from  its  alcoholic  solutions,  and  by 
hydrochloric  acid  from  water  solutions  of  its  salts  of  alkali  metals. 


SUC C INI C   ACID.  45 

When  slowly  distilled,  cinnamic  acid  evolves  cinnamene, 
having  a  persistent  aromatic  odor  resembling  that  of  benzole  and 
naphthalene  together.  Cinnamates  subjected  to  dry  distillation 
emit  the  odor  of  bitter  almond  oil. 

1).  A  saturated  hot-water  solution,  acidulated  with  sulphuric 
acid,  is  treated  with  a  few  cubic  centimetres  of  a  one  per  cent, 
solution  of  permanganate  of  potassium  and  warmed  a  few 
minutes.  If  cinnamic  acid  is  present,  the  odor  of  bitter  almond 
oil  becomes  apparent. — Nitric  acid  with  gentle  heat,  peroxide 
of  lead  in  boiling  solution,  chromate  and  sulphuric  acid  with 
heat,  evolve  bitter  almond  oil  (hydride  of  benzoyl)  from  cinna- 
mic acid — in  most  cases  with  simultaneous  production  of  benzoic 
acid. — Cinnamates  with  strong  nitric  acid  give  off  odor  of 
cinnamon  oil  and  bitter  almond  oil. 

c.  Ferric  salts  with  cinnamates  give  a  yellow  precipitate ; 
manganous  salts  with  excess  of  cinnamates  give  a  white  precipi- 
tate (none  with  benzoates)  ;  copper  salts,  a  greenish-blue  precipi- 
tate; acetate  of  lead,  a  precipitate  not  soluble  in  water,  Pb 
(C9H7O2)2,  from  which  alcohol  washes  out  a  part  of  the  cinnamic 
acid ;  nitrate  of  silver,  a  stable  white  precipitate,  AgC9H7O2, 
insoluble  in  boiling  water ;  baric  and  calcic  salts,  precipitates, 
easily  soluble  in  hot  water. 

32.  SUCCLNTC  ACID.  H2C4H4O4.  Characterized  and 
identified  by  its  physical  properties  (a) ;  its  resistance  to  oxida- 
tion (b) ;  its  reactions  with  iron,  manganese,  lead,  barium, 
calcium,  etc.  (c). — Distinguished  from  cinnamic  acid  by  the 
color  of  its  iron  salt  and  by  not  precipitating  manganous  salts 
(31,  f). — Separated  from  non-volatile  materials  by  sublimation 
(a) ;  from  benzoic  acid  by  insolubility  of  its  barium  salt  in 
alcohol  (30,  <f),  and  by  its  insolubility  in  chloroform  or  ether; 
from  cinnamic  acid  by  the  solubility  of  manganous  succinate 
(30,  c). — Determined  by  extraction  with  ammonia  from  the 
ferric  succinate  (d). 

a.  Crystalline  in   the  monoclmic  system,  generally  rhombic 


46  SOLID     VOLATILE  ACIDS, 

or  hexagonal  plates.  At  130°  C.  (266°  F.)  it  begins  to  emit 
suffocating  vapors,  at  130°  C.  (356°  F.)  it  melts,  and  at  235°  C. 
(455°  F.)  it  sublimes  as  succinic  anhydride  (C4H4O3),  which 
melts  at  120°  C.  (248°  F.)  The  succinic  acid  of  commerce  has 
usually  more  or  less  of  yellow  to  brown  color,  and  of  the  empy- 
reumatic  and  slightly  aromatic  odor  of  oil  of  amber  ;  when 
pure  it  is  white,  and  at  ordinary  temperatures  odorless.  Suc- 
cinic acid  is  soluble  in  about  13  parts  of  water  at  ordinary  tem- 
peratures, in  2J  parts  of  hot  water,  in  30  parts  of  cold  or  20 
parts  of  boiling  alcohol,  sparingly  soluble  in  ether,  not  soluble 
in  chloroform  or  benzole. — Succinic  anhydride  is  more  soluble 
in  alcohol,  but  less  soluble  in  water  than  the  acid. — The  succi- 
nates  of  the  alkali-metals  and  magnesium  are  soluble  in  water ; 
of  the  alkaline  earth-metals,  and  of  most  other  metals  in  diatomic 
salts,  sparingly  soluble ;  ferric  succinate,  insoluble. 

b.  Nitric  acid,  chromic  acid,  and  chlorine  are  without  action 
upon  succinic  acid.     Cold  permanganate  solution  does  not  affect 
free  succinic  acid,  but  with  free  alkali  oxalic  acid   is  formed  with 
deposition  of  binoxide  of  manganese. 

c.  Ferric  chloride,  better  if  slightly  basic,  precipitates  from 
solutions  of  succinates  a  brownish-red  bulky  precipitate  of  basic 
ferric  succinate. — Manganous  salts  do  not  precipitate  succinates. 
— Acetate  of  lead  and  nitrate  of  silver,  each,  give  white  precipi- 
tates of  normal  succinates  slightly  soluble  in  water. — Ammoniacal 
chloride  of  barium  with  alcohol  produces  a  white  precipitate- 
even  in  dilute  solutions. 

Quantitative. — d.  The  ferric  succinate  is  precipitated  from 
dilute  solution  of  succinate  by  addition  of  ferric  chloride,  then 
acetate  of  sodium  in  excess,  and  then  sufficient  ammonia  to 
nearly  or  quite  neutralize  the  mixture.  After  boiling  one-fourth 
of  an  hour,  the  precipitate  is  filtered  out  and  washed,  then  boiled 
with  excess  of  a  five  per  cent,  solution  of  ammonia  and  filtered 
and  washed  with  ammoniacal  water.  The  filtrate  is  evaporated 
on  the  water-bath  until  it  ceases  to  lose  weight,  and  weighed  as 
NH4HC4H4O4.  Or,  for  greater  exactness,  this  salt  while  in 


VE RATE  1C    ACID.  47 

solution  is  treated  with  a  weighed  quantity  of  recently  calcined 
magnesia,  and  the  mixture  evaporated  and  dried  at  150°  C. 
(302°  F.)  The  increase  of  weight  represents  the  succinic 
anhydride. 

33.  SALICYLIC   ACID.     C7H6O3.     (In  most  salts  of  this 
acid  one  atom  of  hydrogen,  in  a  few  salts  two  atoms,  are  replaced 
by  metals.) — Crystalline,  in  monoclinic  four-sided  prisms  or  slen- 
der needles.      Melts  at  125°  to  150°  C.  (257°  to  302°  F.)  and 
sublimes  at  about  200°  C.  (392°  F.)     Its  vapor  causes  irritation 
in  the  throat :  it  has  a  sweetish-sour  taste.     It  has  a  decided  acid 
reaction  upon  test-papers. — It  is  slightly  soluble  in  cold,  moder- 
ately soluble  in  hot  water,  freely  soluble  in  alcohol  and  in  ether. 
— The  salicylates  of  the  alkali  metals  are  insoluble  in  water ; 
those  of  the  alkaline  earth  metals  sparingly  soluble  (that  of  cal- 
cium least) ;  many  of  those  of  other  metals  not  soluble.      The 
dimetallic  salts  are  less  soluble  than  the  monometallic. — With 
ferric  salts,  salicylic  acid  forms  a  deep  violet  color. 

Distilled  or  heated  with  methylic  alcohol  and  concentrated 
sulphuric  acid,  salicylate  of  methyl  is  evolved,  having  the  odor 
of  wintergreen  oil. 

34.  VERATBIC  ACID*     C9H10O4.     Crystallizes  in  slender 
speculse  or  four-sided  prisms,  which  effloresce  at  100°  C.  and  melt 
at  a  higher  temperature,  then  subliming  without  decomposition. 
It  is  sparingly  soluble  in  cold,  freely  in  hot  water,  soluble  in 
alcohol,  insoluble  in  ether — the   solutions   having  a  slight  acid 
reaction.     The  alkaline  veratrates  are  soluble  in  water  and  crys- 
tallizable ;  the  lead  and  silver  salts  insoluble.      It  dissolves  in 
concentrated   nitric   acid,  and  when  this  solution  is  diluted   it 
deposits  nitroveratric  acid,  soluble  in  alcohol,  from  which  it  crys- 
tallizes in  yellow  laminae. 

Veratric  acid  is  separated  from  sebaditta  seeds  (veratrum 
sabadilla)  as  follows  :  They  are  exhausted  with  alcohol  acidulated 
with  sulphuric  acid,  the  solution  is  precipitated  with  milk  of  lime 


48  SOLID    VOLATILE  ACIDS. 

and  filtered,  the  filtrate — containing  veratrate  of  calcium — is  con- 
centrated, treated  with  hydrochloric  acid,  and  left  in  a  cold  place 
to  crystallize.  The  crystals  may  be  purified  by  dissolving  in 
alcohol,  and  filtering  through  animal  charcoal. 

35.  PHEN1C  ACID.  HC6H5O.  Purified  Carbolic  acid. 
Phenol.  Phenylic  alcohol.  '  Coal-tar  creosote. — Characterized 
and  identified  by  its  physical  properties  (a)  ;  by  its  reactions 
with  nitric  acid  (£),  with  ferric  salts  (c),  with  bromine  (d)  and 
chlorine  (e),  as  a  reducing  agent  (/),  and  with  sulphuric  acid 
(<^) . — Distinguished  from  Creosote  by  reacting  with  ferric  salt 
in  more  dilute  solution  (c),  by  gelatinizing  collodion,  by  greater 
solubility  in  ordinary  glycerin,  in  bisulphide  of  carbon,  and  in 
ammonia  water,  and  by  crystallizing  when  pure  (a) . — Separated 
from  Cresylic  acid  and  other  constituents  of  crude  carbolic  acid 
or  from  Fats  by  its  greater  solubility  in  water  (A)  ;  from  solu- 
tion (in  a  greater  quantity  of)  water  by  saturation  with  common 
salt  (i) ;  from  admixture  with  (a  smaller  quantity  of)  water  or 
with  other  substances  by  treatment  with  chloroform  or  bisulphide 
of  carbon  (J)  ;  from  Creosote,  in  part,  by  solution  in  water  (A)  ; 
from  soaps  by  successive  treatment  with  acid,  water,  and  chloro- 
form (fc) ;  from  fixed  and  volatile  oils  by  hot  water. 

a.  Phenic  acid  is  a  colorless-white  solid,  crystallizing  in  long 
needles  of  the  trimetric  system,  melting  at  34°  to  41°  C.  (93°  to 
106°  F.),  and  distilling  at  182°  to  186°  C.  (359°  to  367°  F.)  It 
has  a  strong  and  persistent  odor,  resembling  creosote  but  some- 
what aromatic,  a  biting  taste,  and  (when  concentrated)  a  bleach- 
ing and  shrivelling  effect  on  the  skin.  It  does  not  redden  litmus. 
— It  is  soluble  in  20  parts  of  water  at  ordinary  temperatures,  and 
dissolves  two  or  three  per  cent,  of  water,  being  thereby  liquefied 
— hence  is  deliquescent  in  the  air.  It  is  soluble  in  all  proportions 
of  alcohol,  ether,  chloroform,  bisulphide  of  carbon,  and  glycerin 
(absolute  or  ordinary) ;  in  20  parts  of  benzole ;  readily  soluble 
in  fixed  oils  and  many  volatile  oils,  and  in  aqueous  solutions  of 
potassa  and  soda. — The  last-named  mixtures  or  compounds, 


P HE  NIC   ACID.  49 

sometimes  termed  phenates,  are  not  of  definite  proportions,  but 
are  crystallizable,  and  are  soluble  in  alcohol  and  ether.  Phenic 
acid  does  not  decompose  carbonates,  but  mixes  with  aqueous 
alkaline  carbonates. — It  coagulates  albumen  and  gelatin  and 
collodion  (ether-solution  of  gun-cotton). 

I.  To  a  few  drops  (or  a  small  fragment)  of  the  material  to 
be  tested  add  a  drop  or  two  of  concentrated  nitric  acid.  Then 
add  a  slight  excess  of  potassa,  and  if  color  has  appeared  dilute 
with  water.  The  yellow  color  of  nitrophenic  acid  (36,  a)  is 
apparent  in  10,000  parts  of  water ;  of  the  potassic  nitrophenate 
in  50,000  parts  of  water  ;  the  column  having  the  depth  of  half 
an  inch.*  The  nitrophenic  acid  may  be  extracted  from  water  by 
benzole  or  ether. 

c.  Very  dilute  solution  of  ferric  chloride  gives  a  blue  color 
with  aqueous  solution  of  phenic  acid — the  color  being  permanent 
(distinction  from  that  of  Morphia),  but  destroyed  by  boiling 
(distinction  from  that  of  Tannic  acid).     Oxalic  acid  destroys  the 
color,  and  many  organic  substances  prevent  its  formation ;  it  is 
not  extracted  by  benzole  or  chloroform. 

In  this  test,  the  result  is  distinguished  from  a  similar  one  with 
Creosote  by  the  following  precautions  (FLUCKIGEB)  :  1st,  take 
1  part  of  solution  of  ferric  chloride  of  specific  gravity  1.34, 
and  9  parts  of  the  liquid  to  be  tested  (with  pure  carbolic  acid 
the  mixture  has  a  yellowish  hue;  with  pure  creosote,  no  color). 
2d,  add  5  parts  of  85  per  cent,  alcohol  (with  pure  carbolic  acid, 
a  clear  brown  liquid;  with  pure  creosote,  a  green  solution). 
3d,  add  60  parts  of  water ;  with  pure  creosote,  the  result  is  a 
dingy  brownish  color ;  if  phenic  acid  is  present,  a  fine  blue  color 
appears. 

d.  Bromine  water  gives  a  yellowish-white  precipitate  in  even 
very  dilute  solutions  of  phenic  acid  (the  same  with  Creosote). 

e.  Chlorine  gas  (from  chlorate  of  potassium  and  hydrochloric 
acid)  forms  a  deep  yellow  color — chloride  of  phenyl. 

*  PRBSCOTT  :  Proceedings  Am.  Phar.  Asso.,  xix.,  560,  and  Chem.  News, 
xxvi.,  369. 


50  SOLID    VOLATILE    ACIDS. 

f.  Alkaline  cupric  solution  is  not  reduced  by  (pure)  phenic 
acid  (is  reduced  by  crude  "carbolic  acid").     Mercury  and  silver 
salts  are  only  slowly  reduced  by  boiling  with  phenic  acid  (are 
reduced  by  impure). 

Permanganate  solution  is  reduced  by  pure  phenic  acid,  in 
solutions  acid  or  alkaline,  with  separation  of  binoxide  of 
manganese. 

g.  With   sulphuric   acid — equal   parts    of    the   concentrated 
acids  at  290°  C.  for  a  quarter  of  an  hour  furnishing  the  best 
result — Sulphophenic  acid  is  formed  (37). 

Quantitative. — h.  Cresylic  acid  and  other  admixtures  (as 
fats)  nearly  or  quite  insoluble  in  water  may  be  approximately 
separated  and  determined  by  solution  with  20  parts  of  water. 
In  a  cylindrical  graduate  of  J  litre  (or  larger)  capacity,  place 
10  c.c.  of  the  carbolic  acid  or  mixture  under  examination,  add 
200  c.c.  of  water,  agitate,  and  set  aside.  Read  from  the  bottom 
the  number  of  c.c.  of  impurities. 

i.  Phenic  acid  may  be  approximately  separated  from  water 
solution  by  adding  chloride  of  sodium  as  long  as  the  latter  dis- 
solves. If  the  operation  be  performed  in  a  cylindrical  graduate, 
as  above,  the  layer  of  phenic  acid  is  read  from  the  top. 

j.  Phenic  acid  may  be  approximately  deprived  of  water  and 
the  amount  of  the  latter  ascertained  by  mixture  with  chloroform 
or  bisulphide  of  carbon,  In  a  graduate  of  a  little  more  than 
20  c.c.  capacity  (a  test-glass  or  test-tube  may  be  graduated  for 
the  purpose),  place  10  c.c.  of  the  phenic  acid  under  examination 
and  add  10  c.c.  of  the  chloroform  or  bisulphide  of  carbon,  agi- 
tate, stopper,  and  set  aside  a  few  hours.  Read  off  from  the  top 
the  amount  of  water  separated. — Phenic  acid  may  be  separated 
from  various  mixtures  in  the  same  manner ;  for  this  purpose  the 
mixture  should  be  made  neutral  to  test-paper,  if  not  so  already. 
The  chloroform  or  bisulphide  of  carbon  may  be  removed  by 
evaporation  in  a  warm  place. 

k.  In  separation  of  phenic  acid  from  soaps,  the  latter  is 
decomposed  by  digestion  with  dilute  sulphuric  acid  and  hot 


NITROPHENIG   ACID.  51 

water ;  when  cold,  the  fat  acid  is  separated,  by  use  of  a  wet  filter 
if  necessary,  and  washed  with  water ;  and  the  water  solution  and 
washings  exhausted  with  chloroform.  The  chloroform  may  be 
distilled  from  the  phenic  acid,  and  if  necessary  the  distillation 
repeated. 

36.  NITBOPHENIC  ACID.  HC6H2(NO3)3O.  (Trinitro- 
phenic  acid.)  Trinitrophenol.  Carbazotic  acid.  Picric  acid. — 
Identified  by  its  physical  properties,  especially  its  intense  color- 
ing effects  (a)  ;  its  precipitation  of  alkaloids  (b) ;  its  reactions 
with  special  reagents  (c). — Separated  from  water  solutions  by 
extraction  with  chloroform,  etc.  (a) ;  by  crystallization  as  a 
potassium  salt  (d). — Determined  as  salt  of  oinchonia  (e). 

a.  In  bright  yellow  crystalline  scales  or  in  octahedrons  of  the 
trimetric  system.  It  melts  when  slowly  heated  and  afterward 
sublimes ;  when  quickly  heated  it  explodes.  It  has  a  very  bitter 
and  somewhat  acrid  and  sour  taste,  and  when  heated  a  suffocating 
odor  and  effect.  It  reddens  litmus. 

It  is  soluble  in  100  parts  of  water  at  15°  C.  (59°  F.)  and  in 
25  parts  at  80°  C.  (176°  F.),  less  soluble  in  water  acidulated 
with  mineral  acids,  and  freely  soluble  in  alcohol,  ether,  chloro- 
form, benzole,  petroleum  naphtha,  and  amylic  alcohol.  These 
solvents,  which  are  not  miscible  with  water,  remove  nitrophenic 
acid  from  water  by  aid  of  acidulation  with  sulphuric  acid.  The 
solutions  have  a  yellow  color,  perceptible  when  very  dilute ; 
except  solutions  in  benzole,  petroleum  naphtha,  and  dilute  sul- 
phuric acid,  which  are  colorless. 

The  colorless  as  well  as  colored  solutions  stain  white  paper, 
and  more  permanently  stain  the  skin  and  fabrics  of  nitrogenous 
composition. 

The  normal  metallic  picrates  are  all  soluble  in  water,  that 
of  potassium  being  one  of  the  least  soluble,  and  requiring  260 
parts  of  cold  or  14  parts  of  boiling  water  for  solution.  This  salt 
is  insoluble  in  alcohol. — Many  of  the  picrates  explode  more 
violently  than  the  free  acid,  and  oxidizable  agents  in  intimate 


52  SOLID    VOLATILE    ACIDS. 

contact  facilitate  explosion,  which  may  occur  by  trituration  or 
pressure. 

b.  Solution  of  salts  of  most  of  the  alkaloids  precipitate  nitre--, 
phenic  acid  or  its  soluble  salts — the  cinchona  alkaloids,  the  opium 
alkaloids,    except   morphia   and   pseudomorphia,    the    strychnos 
alkaloids,  veratria,  berberina,  colchicia,  and  delphinia,  Deing  fully 
precipitated  from  solution  even  when  dilute  and  well  acidulated 
with  sulphuric  acid.     Morphia  is  precipitated  from  moderately 
concentrated  solutions  having  little  or  no  free  acid.     The  preci- 
pitates   are    yellow,    and   are   dissolved   by    hydrochloric   acid. 
Compare  135,  e. 

c.  With    ammoniacal  cupric  sulphate    solution,   nitrophem'c 
acid  forms  a  green  precipitate. — Potassic  cyanide,  or  potassic 
sulphide,  or  grape  sugar,  with  nitrophenic  acid   and  excess  of 
potassa,  in  hot  solution,  gives  a  blood-red  solution  (yellow  when 
greatly   diluted)   from   formation  of  isopurpurate  of  potassium 
(the  crystals  of  which  arfe  green  by  reflected   light) . — If  ferrous 
sulphate  is  boiled  in  solution  with  nitrophenic  acid,  treated  with 
excess  of  ammonia   and  filtered,    the    filtrate    concentrated  and 
acidulated    with    acetic   acid,  bright-red    crystals    of  picramic 
acid    are    formed.       Stannous     chloride    and    several     other 
reducing    agents    may    be    substituted    for    the    ferrous    salt. 
Picramic   acid   is    nearly    insoluble    in   water,    but   soluble   in 
alcohol  or  ether. 

d.  The  graded  solubility  of  potassic  nitrophenate  in  hot  and 
cold  water  and  in  alcohol  (a)  enables  this  salt  to  be  almost  per- 
fectly removed  from  solution,  in  beautiful   crystals,  by  gradual 
cooling  of  the  hot  water  solution,  with  gradual  addition  of  alco- 
hol after  crystallization  has  ceased  in  the  cold  water. 

Quantitative. — e.  Nitrophenic  acid  or  a  soluble  salt  of  this 
acid  is  precipitated  by  a  solution  of  sulphate  of  cinchonia  acidu- 
lated with  sulphuric  acid,  the  precipitate  is  washed  with  water, 
dried  at  a  very  gentle  warmth,  then  heated  (and  melted)  on  the 
water-bath  and  weighed.  CaoH34N2  (C6H2[NO2]3O)2  :  2HC6H2 
(N02)30:  :  1  :  0.6123. 


LACTIC   ACID, 

37.  SULPHOPHENIC  ACID.  HC6H6SO4,  Phenyl  sul- 
phuric acid.  Sulphophenylic  acid.  Sulphocarbolic  acid. — Only 
preserved  in  its  salts,  which  are  stable  and  crystallizable  com- 
pounds, decomposed  by  nitric  acid  with  the  formation  of  nitro- 
phenic  acids  (35,  b),  and  very  gradually  decomposed  by  boiling 
in  solution  with  formation  of  sulphates  and  phenic  acid.*  Free 
sulphophenic  acid  evolves  phenic  acid  when  heated  to  the  boiling 
point  of  the  latter. — The  sulphophenates  are  all  soluble  in  water, 
and  mostly  soluble  in  alcohol. 


LIQUID   NON-VOLATILE   ACID. 

38.  LACTIC  ACID.  HC3H6O3.  Characterized  by  its 
physical  properties  (a) ;  by  the  solubility  and  crystalline  form 
of  its  salts  (b) ;  by  the  extent  of  its  reducing  power  (c) . — 
/Separated  from  many  acids  by  the  solubility  of  its  lead  salt  in 
water,  alcohol,  and  ether  (d)  ;  from  glycerin,  sugar,  etc.,  by  the 
insolubility  of  its  zinc  salt  in  alcohol  (f)  ;  from  tissues,  etc.,  as 
below  (e). — Determined  by  saturation  with  alkali  (g) ;  by  weight 
of  zinc  or  magnesium  salt  (h). 

a.  Absolute  lactic  acid  is  a  colorless,  odorless,  syrupy  liquid, 
of  a  very  acid  taste.  Pure,  it  has  the  spec.  grav.  1.248;  when 
75  per  cent.,  the  spec.  grav.  1.212.  Not  volatile  without  decom- 
position; not  decomposed  by  heat  below  130°  C. ;  at  145°  C. 
vaporizes  dilactic  acid,  at  higher  temperature  lactide,  both  of 
which  are  converted  to  lactates  by  the  alkalies. — Soluble  in  all 
proportions  of  water,  alcohol,  and  ether ;  slightly  soluble  in 
chloroform.  (Gly eerie  acid,  C3H6O4,  which  resembles  lactic 
acid,  is  insoluble  in  ether.)  Concentrated  sulphuric  acid  mixes 
with  lactic  acid  without  blackening  it.  Heated  on  platinum  foil, 
it  leaves  a  slight  carbon  residue  which  burns  wholly  away. 

*  PRESCOTT  :  Chem.  News,  xxvi.,  269. 


54  LIQUID  WON- VOLATILE  ACID. 

#,  The  metallic  lactates  are  all  soluble  in  water;  being 
mostly  sparingly  soluble  in  cold,  freely  in  boiling  water.  Cal- 
cium lactate  is  soluble  in  9^  parts  (sarcolactate  in  12J  parts)  of 
cold  water,  soluble  in  alcohol,  not  in  ether.  Barium  lactate  is 
soluble  in  water  and  alcohol,  insoluble  in  ether.  Zinc  lactate  is 
soluble  in  58  parts  of  cold,  6  parts  of  boiling  water ;  insoluble 
in  alcohol  (sarcolactate  in  6  parts  cold  water  and  in  2.2  parts  cold 
alcohol).  Silver  lactate  is  soluble  in  water  and  in  hot  alcohol. 
Lead  lactate  is  freely  soluble  in  water,  sparingly  soluble  in  cold, 
readily  in  hot  alcohol,  slightly  soluble  in  ether.  (Glycerate  of 
lead  is  but  slightly  soluble  in  cold  water.) 

Calcium  lactate  (saturated  with  base)  crystallizes  in  small 
white  mammillated  tufts,  seen  under  the  microscope  to  consist 
of  delicate  needles,  some  of  which  resemble  a  bundle  of  bristles 
bound  midway  between  the  ends.  The  acid  lactate  of  calcium 
(supersaturated  with  acid)  forms  white  hemispheres,  compactly 
made  of  radiate  needles,  trimetric.  Zinc  lactate  crystallizes 
from  concentrated  solutions  in  shining  crusts,  from  dilute  solu- 
tions in  four-sided  prismatic  needles  ;  the  crystals,  Zn(C3H5O3)a. 
3H2O,  lose  their  water  rapidly  at  100°  C.,  and  the  salt  decom- 
poses above  210°  C.  (Zinc  Sarcolactate  crystallizes  in  slender 
needles,  Zn(C3H5O3)2.2H2O,  losing  their  crystal  water  very 
slowly  at  100°  and  giving  off  empyreumatic  vapors  below  150°.) 
Silver  lactate  crystallizes  from  neutral  solutions,  in  slender 
needles,  grouped  in  nodules,  quickly  blackening  in  the  light. 

c.  Lactic  acid  does  not  reduce  the  alkaline  solution  of  sul- 
phate of  copper,  but  quickly  reduces  potassium  permanganate 
from  acid  or  alkaline  solutions. 

d.  Lactic   acid   may  be  separated   from    acids  which  form 
insoluble  lead  salts  (and  other  insoluble  bodies),  according  to  the 
general  method  given  at  40,  g,  either   in   alcoholic  or  aqueous 
solution.     In  a  similar   manner   it    is    removed    from    insoluble 
"barium  salts,  as   soluble   barium  lactate,  after   saturation  with 
carbonate   of  barium.     The  barium   is  then  removed  from  the 
filtrate  by  precipitation  with  sulphuric  acid  and  filtration,   and 


FORMIC  ACID.  55 

the  sulphuric  acid  is  removed  from  the  lactic  acid  in  the  last 
filtrate  by  repeatedly  adding  a  mixture  of  1  part  of  alcohol  and 
5  parts  of  ether  and  evaporating. 

e.  Also,  the  fluid  obtained  by  digestion  and  expression  of 
tissues  may  be  treated  with  sulphuric  acid  to  fix  albuminous 
matters,  filtered,  treated  with  alcohol  and  five  times  its  weight 
of  ether  and  again  evaporated,  filtering  when  necessary,  till  the 
sulphuric  acid  is  removed. 

/.  A  (weighed)  quantity  of  the  material  containing  lactic  acid, 
mixed  with  substances  soluble  in  alcohol,  is  saturated  in  aqueous 
solution  with  oxide  of  zinc,  the  mixture  evaporated  to  dryness, 
the  residue  digested  in  alcohol  and  filtered.  The  filtrate  will 
contain  the  substances  soluble  in  alcohol ;  the  residue  will  contain 
zinc  lactate,  soluble  in  water. 

Quantitative. — g.  In  the  acidimetry  of  lactic  acid,  one- 
tenth  equivalent,  9.000  being  taken,  the  required  number  of 
cubic  centimeters  of  normal  solution  of  alkali  equals  the  number 
per  cent,  of  HC3H5O3. 

U.  Saturating  with  oxide  of  zinc  or  oxide  of  magnesium, 
filtering  and  washing  with  water,  crystallizing  or  evaporating, 
and  drying  at  100°  C. : 

Mg(C3H603)2  :  2HC3H503  :  :  1  :  0.8911. 
Zn(C3H603)2  :  2HC3H6O3  :  :  1  :  0.7402. 


LIQUID   VOLATILE   ACIDS. 

39.  FORMIC  ACID.  HCHO2.  Identified  by  its  odor  (a) ; 
by  its  reducing  power  upon  salts  of  the  noble  metals,  permanga- 
nates, chromates,  etc. — the  radical  CHO2  being  oxidized  to  H2O 
and  CO2 — (b) ;  by  the  color  of  its  ferric  salt  in  solution  (c) ;  by 
the  odor  of  its  ethyl  salt  (d). — Separated  from  substances  less 


56  LIQUID  VOLATILE  ACIDS. 

volatile  by  distillation  (/) ;  from  organic  acids  in  general  by  the 
solubility  of  its  lead  salt  in  water  (g) ;  from  acetic  acid  by  the 
insolubility  of  its  lead  salt  and  its  magnesium  salt  in  alcohol 
(7i). — Determined  by  acidimetry  (_/),  or  by  oxidation  to  carbonic 
anhydride  (&). 

a.  The  odor  of  formic  acid  is  pungent,  irritating,  character- 
istic,  slightly   acetous,  and  of  an  intensity  varying  greatly  with 
the  strength  and  temperature  of  its  solutions.     In  contact  with 
the  skin,  it  causes  intense  irritation. 

b.  Nitrate    of  silver   in   concentrated   solution  gives,  with 
solutions  of  formates,  the  white  crystalline  precipitate  of  formate 
of  silver,  not  formed  with   free   formic   acid.     The   precipitate 
darkens   upon   standing  a  short  time,  and  when  warmed  it  is 
quickly  reduced  to  metallic  silver.     In  case  the  formic  acid  is 
free,  or  the  formate  in  dilute  solution,  so  that  formate  of  silver  is 
not  precipitated,  the  reduction  of  metallic  silver  occurs  slowly  in 
warm  solution.     An  excess  of  ammonia  retards  or  prevents  the 
reduction.     Mercuric   chloride    in    hot    solution    is    gradually 
reduced  by  formic  acid,  more  readily  by  formates,  a  white  preci- 
pitate  of  mercurous  chloride  forming  first,  then  a  dark  gray 
precipitate  of  metallic  mercury.     Alkaline  chlorides  and  acetic 
acid  retard  or  prevent  the  reduction.     Solution  of  potassic  per- 
manganate is  slowly  decolorized  at  ordinary  temperatures,  and 
warm  solution  of  chromic  acid  is  gradually  turned  green,  by 
sufficient  formic  acid  or  formates. 

Chlorine  and  bromine  oxidize  formic  acid  to  carbonic  anhy- 
dride and  hydracid.  Nitric  acid  also  decomposes  it,  likewise 
peroxide  of  mercury  in  boiling  solution  (removal  from  acetic 
acid,  see  i). 

c.  Ferric  chloride  solution  with  formates  produce  a  red  solu- 
tion of  ferric  formate. 

d.  With  alcohol  and  sulphuric  acid,  at  a  gentle  heat,  formic 
acid  becomes  formate  of  ethyl,  C2H5CHOa,  an  ether  having  a 
strong,  agreeable  odor,  like  that  of  peach-kernels,  and   distilling 
at  about  55°  C. 


FORMIC   ACID.  57 

e.  Strong  sulphuric  acid,  at  a  gentle  heat,  decomposes. 
HCHO3  into  H2O  and  CO.  Strong  alkalies  at  a  gentle  heat 
convert  formic  acid  into  oxalates /  at  a  higher  heat  carbonates 
are  formed  with  liberation  of  carbonic  oxide. 

f.  Absolute  formic  acid  distils  at  100° ;    the  aqueous  solu- 
tion, 77.5  per  cent,  of  acid,  at  ordinary  atmospheric  pressure, 
boils  at  107.1°,  and  mixtures  containing  larger  or  smaller  pro- 
portions of  water  are  reduced  to  this  per  cent,  of  acid  and  boil- 
ing-point  by    repeated   distillations.     A  glycerin-bath   may    be 
used.     Formic  and  acetic  acids  are  not  easily  separated  by  frac- 
tional  distillation.     Dilute  sulphuric  acid  is  employed  for  the 
production  of  formic  acid  from  formates. 

g.  The  formates  are  all  soluble  in  water.     Plumbic  formate 
requires  40  parts  of  cold  water  or  a  smaller  proportion  of  hot 
water  for  solution.    Argentic  formate  is  sparingly  soluble  in  cold 
water,  decomposed  by  hot  water  (#).     Mercurous  formate  is  the 
least  soluble  salt  of  this  acid,  requiring  about  500  parts  of  cold 
water  for  solution.     It  is  much  more  soluble  by   hot  water,  in 
which  it  decomposes. — In  alcohol,  the  formates  of  lead,  magne- 
sium, calcium,  and  barium   are  insoluble,  the   alkaline  formates 
soluble. 

Formic  acid  is  separated  from  far  the  larger  number  of 
organic  acids  by  precipitation  of  the  latter  as  lead  salts.  With 
free  acids,  the  method  given  for  acetic  acid  (40,  g)  may  be 
employed,  avoiding  the  use  of  heat  in  any  part  of  the  operation. 

h.  Formic  acid  is  separated  from  Acetic  acid  by  saturating 
with  magnesia,  or  with  lead  oxide  or  carbonate,  adding  much 
alcohol,  filtering  and  washing  with  alcohol.  In  the  preparation 
of  formic  acid,  acetic  acid  is  approximately  separated  by  the 
crystallization  of  plumbic  formate  from  water  solution  contain- 
ing also  plumbic  acetate. 

i.  Formic  acid  is  removed  from  acetic  acids,  or  from  other 
acids  not  very  easily  oxidized,  by  hot  digestion  with  mercuric 
oxide,  until  effervescence  ceases.  HgO  and  HCHO2  form  H2O 
and  CO2  and  Hg.  The  filtrate  will  contain  mercuric  acetate  if 


58  LIQUID    VOLATILE  ACIDS. 

acetic  acid  were  present ;  in  fact,  the  presence  of  mercury  in  the 
filtrate  indicates  some  other  acid  besides  formic.  Acids  forming 
insoluble  mercury  salts  may  be  obtained  from  the  residue,  by 
treatment  with  hydrosulphuric  acid,  filtration,  and  dissipation  of 
the  excess  of  hydrosulphuric  acid  in  the  last  filtrate. 

Quantitative.—/.  Free  formic  acid  may  be  determined  by 
the  ordinary  methods  of  acidimetry.  See  40,  i,  j.  Or  the  acid 
may  be  saturated  with  pure  carbonate  of  barium,  and  the 
formate  of  barium  precipitated  as  a  sulphate — BaSO4  : 
2HCH02  :  :  1  :  0.395. 

Tc.  Formic  acid  is  quantitatively  separated  from  acetic  acid 
by  precipitation  with  alcoholic  solution  of  plumbic  acetate, 
washing  the  precipitate  with  alcohol.  The  formate  of  lead  may 
be  determined,  after  oxidation  with  chromate  and  an  acid,  as 
carbonic  anhydride.  The  lead  formate,  with  solution  of  bichro- 
mate of  potassium,  is  placed  in  an  apparatus  for  determination 
of  carbonic  anhydride  (from  carbonates  whose  bases  form 
insoluble  sulphates),  and  decomposed  by  nitric  acid,  gradually, 
as  the  dry  gas  escapes,  in  the  usual  manner.  CO2  :  HCHO2  :  : 
1  :  0.956.  Or,  the  carbonic  anhydride  may  be  received  in  an 
ammoniacal  solution  of  chloride  of  barium.  BaCO3  :  HCHO2 
:  :  1  :  0.233. 

40.  ACETIC  ACID.  HC2H3O2.  Identified  by  its  odor  (a), 
by  the  odor  of  its  ethyl  salt  (b),  by  the  odor  arising  from  the  igni- 
tion of  its  salts  alone  (c)  or  with  arsenious  acid  (d),  by  the  color 
of  its  ferric  salt  in  solution  (e),  by  the  free  solubility  of  its  lead 
salt  and  the  sparing  solubility  of  its  silver  salt  (/"). — Separated 
from  less  volatile  or  more  volatile  substances,  by  distillation  (h) ; 
from  the  larger  number  of  acids,  by  the  solubility  of  its  lead  salt 
(<?). — Determined  as  free  acid,  or  in  salts  of  insoluble  bases,  by 
its  saturating  power  (i,  j). 

a.  Aqueous  acetic  acid  evolves  the  odor  of  vinegar,  which  is 
pungent  in  proportion  to  the  strength  and  temperature  of  the 
solution.  Acetates  impart  the  same  odor  in  a  very  slight  degree. 


ACETIC   ACID.  59 

d.  The  acetate  of  ethyl,  C2H6  C2H3O2,  is  obtained  by  warming 
acetic  acid  or  its  salts  with  sulphuric  acid  and  a  small  propor- 
tion of  alcohol.  It  is  recognized  by  its  pungent  and  fragrant  odor, 
ethereal,  refreshing,  and  obscurely  acetous.  It  distils  at  74°,  and 
may  be  cleared  from  acids  and  from  water  by  contact  with  dry 
carbonate  of  potassium.  It  is  neutral  to  test-paper,  and  is  solu- 
ble in  about  ten  parts  of  water. 

c.  When  ignited  in  a  tube  closed  at  one  end,  most  of  the 
metallic  acetates  evolve  acetone,  C3H6O,  a  vapor  of  an  agreeable 
odor,    readily    burning   with   a   white   flame.      Liquid    acetone 
boils  at  56°. 

d.  If  acetates  are  heated  with  fixed  alkali  and  arsenious  acid, 
the  offensive  odor  of  cacodyl  is  observed,  As2(C2H5)2  H2O. 

e.  Solutions  of  ferric  salts,  with  solutions  of  acetates  (not 
with  hydric  acetate),  form  a  dark  red  solution  of  ferric  acetate, 
Fe2(C2HgO2)6,  decolorized  by  strong  sulphuric  or  hydrochloric 
acid  (distinction  from  Meconate),  not  decolorized  by  solution  of 
mercuric  chloride  (distinction  from  Sulphocyanate),  precipitated 
as  basic  acetate  by  boiling. 

f.  The  metallic  acetates  are   soluble  in  water,  argentic  and 
mercurous  acetates  being  sparingly  soluble  and  forming  as  crys- 
talline precipitates  from  concentrated  solutions.    Argentic  acetate 
forms  white,  fine,  scaly  crystals,  soluble  in  one  hundred  parts  of 
cold  water  and  in  a  smaller  proportion  of  hot  water.     Mercurous 
acetate  forms  scaly  crystals,  sparingly  soluble  in  water,  more 
soluble  in  dilute  acetic  acid.     The  normal  and  basic  acetates  of 
lead  are  freely  soluble   in  water.     In   alcohol,    mercurous  and 
argentic    acetates    are    nearly    insoluble,    mercuric    acetate    is 
slowly  decomposed,  normal   lead  acetate  freely  soluble,  basic 
lead   acetates   sparingly    soluble,    the    other    metallic    acetates 
soluble.     Zinc   acetate   crystallizes   in   hexagonal    plates,    very 
soluble  in  water. 

g.  The  solubility  of  its  lead  salt  enables  (free)  acetic  acid  to 
be  separated  from  organic  acids  in  general  (not  lactic,  formic, 
butyric,  valeric) — in  qualitative  or  quantitative  work — as  follows: 


60  LIQUID  VOLATILE  ACIDS. 

Digest  the  acids  in  a  closed  flask  at  a  gentle  heat  with  sufficient 
oxide  of  lead,  until  the  mixture  is  just  alkaline  to  litmus  ;  filter 
and  wash.  For  complete  separation  from  tartaric  acid,  or  other 
acid  having  its  lead  salt  appreciably  soluble  in  water  but  insoluble 
in  alcohol,  the  solution  should  be  alcoholic  and  the  washing  wholly 
by  alcohol,  avoiding  the  use  of  much  excess  of  oxide  of  lead. 

Residue  (A)  ;  plumbic  salts  of  organic  acids  (excess  of  oxide  of  lead). 

Filtrate  (B)  •  plumbic  acetate  (basic  and  not  freely  soluble  in  alcohol). 

Treat  nitrate  B,  in  a  long-necked  flask,  with  washed  hydrosulphuric 
acid  gas,  to  complete  precipitation  ;  filter  and  wash  with  water. 
Return  the  filtrate  and  washings  to  the  flask,  insert  therein  a  glass 
tube  and  blow  air  from  a  bellows  through  the  same  until  the 
hydrosulphuric  acid  is  expelled. 

Filtrate  (c)  :  acetic  acid  (lactic  acid  ;  formic  acid  ;  butyric  acid  ;  valeric 
atid). 

Treat  residue  A  with  washed  hydrosulphuric  axjid  gas,  until  the 
residue  appears  wholly  black,  as  seen  from  beneath  the  vessel. 
Filter  and  wash,  and  expel  the  hydrosulphuric  acid  from  the 
filtrate  by  a  current  of  air  from  a  bellows,  as  described  above. 
Filtrate  (D)  :  acids  whose  lead  salts  are  insoluble  in  water  (or  alcohol). 

Ji.  Acetic  acid  boils  at  119°.  It  may  be  distilled  from  a 
paraffin  or  glycerin  bath.  In  distillation  from  sulphuric  acid,  the 
acetic  acid  is  liable  to  be  oxidized  to  a  slight  extent,  with  pro- 
duction of  carbonic  and  sulphurous  anhydrides,  the  latter  con- 
densing with  the  acetic  acid.  For  the  acidimetry  of  the  distillate, 
acetates  should  be  distilled  with  phosphoric  acid  (or  with 
hydrochloric  acid,  and  the  subsequent  determination  of  the  latter 
by  standard  solution  of  silver).  Fractional  distillation — with  or 
without  fractional  saturation — may  be  employed  in  the  separa- 
tion of  acetic  acid  from  other  acids  more  or  less  volatile  than 
itself.  (See,  also,  Valeric  acid,  c.) 

Quantitative. — i.  Free  acetic  acid,  in  absence  of  other 
acids,  may  be  determined  by  neutralization  with  an  ascertained 
quantity  of  alkali.  Different  alkalies  have  been  used  in  standard 
solution  for  this  purpose — as  soda,  potassa,  sodic  carbonate,  lime 
dissolved  with  sugar,  ammonio-cupric  sulphate.  In  the  solid 
state,  calcined  magnesia,  crystallized  sodic  carbonate,  and  potassic 


BUTYRIC  ACID.  61 

bicarbonate  have  been  employed.  Also  baric  carbonate,  the 
barium  dissolved  as  acetate  being  then  determined  as  sulphate. 

In  testing  colorless  or  slightly  colored  solutions  with  any  of 
the  standard  solutions  named  above,  except  that  of  ammonio- 
cupric  sulphate,  the  point  of  saturation  is  indicated  by  litmus ; 
but  in  case  the  acetic  solution  is  colored  somewhat,  a  little  sul- 
phate of  copper  may  be  added,  when  the  neutral  point  will  be 
indicated  by  the  cloudiness  due  to  the  commencing  precipitate 
of  hydrate  of  copper.  With  the  ammonio-cupric  standard 
solution,  the  solution  determined  must  be  very  dilute,  when 
saturation  will  be  shown  by  the  turbidity.  In  the  use  of  cal- 
cined magnesia,  saturation  is  indicated  by  the  dissolving  of  the 
solid,  as  well  as  by  the  color  of  litmus. 

In  the  metho4  with  carbonate  of  barium,  the  acid  is  saturated 
with  the  pure  carbonate;  the  acetate  of  barium  filtered  and 
washed  from  the  excess  of  the  reagent,  precipitated  by  dilute 
sulphuric  add  and  weighed  as  barium  sulphate.  BaSO4  :  2H 
C2H302  :  :  1  :  0.515. 

The  most  convenient  standard  of  solutions  of  alkalies  are 
the  "  normal  solutions,"  operating  upon  one-tenth  equivalent  of 
the  acid — HC2H3O2 — 6.000  grams  of  the  material. 

y.  The  acetic  acid  producible  from  acetates  of  bases  insoluble 
in  water  may  be  estimated  volumetrically,  as  follows  :  To  a 
solution  of  C.OOO  grams  of  the  acetate,  add  normal  solution  of 
alkali  to  complete  precipitation,  noting  the  number  of  cubic 
centimeters  used.  Filter  and  wash  till  the  washings  do  not 
affect  litmus-paper.  To  the  filtrate  and  washings,  add  of  a 
normal  solution  of  acid  to  the  neutral  point.  The  number  of 
cubic  centimeters  of  alkali  used,  minus,  the  number  of  cubic 
centimeters  of  acid  used,  expresses  the  per  cent,  of  acetic  acid 
sought. 

41.  BUTYRIC  ACID.  HC4H7O2.  Identified  by  its  odor 
(a) ;  by  the  odor  of  its  ethyl  salt  (b) ;  by  its  liquidity, 
solubilities,  and  the  properties  of  its  salts  of  lead,  barium,  and 


62  LIQUID   VOLATILE  ACIDS. 

other  metals  (c). — Separated  from  acids  having  higher  or  lower 
boiling  points  by  fractional  saturation  and  distillation  (d) ;  from 
many  acids  by  the  solubility  of  its  lead  salt  in  water,  and  from 
other  acids  by  the  solubility  of  its  lead  salt  in  alcohol  (c.  See 
process  g,  under  Acetic  acid). — Determined  by  saturation  (e) ; 
by  ultimate  analysis. 

a.  The  odor  of  butyric  acid  is  like  that  of  rancid  butter,  but 
somewhat  less   offensive,  and  obscurely  acetous,  closely  resem- 
bling that  given  by  slightly  rancid  butter  when  heated.     It  is  a 
strong  and  persistent  odor,  not  much  diminished  by  dilution  of 
the  acid,  but  increased  by  warming  it.     The  metallic  buty rates 
are  odorless,  unless  undergoing  decomposition. 

b.  Butyric   ether — C2H5C4H7O2 — is    formed    by    warming 
butyric  acid  or  a  butyrate  with  alcohol  and  excess  of  sulphuric 
acid.     It  has  the  odor  of  pineapples,  by  which  it  is  readily  iden- 
tified.    It  rises  to  the  surface  of  aqueous  mixtures,  and  may  be 
decanted,  and  purified  from  acid  by  addition  of  chalk  and  from 
water  by  chloride  of  calcium.     It  is  soluble  in  all  proportions 
of  alcohol  and  ether,  very  slightly  soluble  in  water.      It  distils 
at  119°  C. 

c.  Absolute  butyric  acid  is  a  colorless,  mobile  liquid,  solidi- 
fied at  very  low  temperatures,  at  15°  C.  having  a  specific  gravity 
of  .974.     It  is  soluble  in  all  proportions  of  water,  alcohol,  ether, 
and  wood-spirit.     It  is  not  soluble  in  concentrated  solutions  of 
freely  soluble  salts.     The  metallic  butyrates  are  all  soluble  in 
water;    plumbic,    argentic,    and   mercurous    sparingly    soluble; 
calcic  freely  soluble  in  cold  water,  but  sparingly  soluble  in  hot 
water.     Plumbic  butyrate  is   more  soluble  in  alcohol  than  in 
water ;  argentic  butyrate  less  soluble  in  alcohol  than  in  water ; 
baric  butyrate  very  sparingly  soluble  in  alcohol ;  potassic  buty- 
rate freely  soluble  in  alcohol. 

Butyrate  of  lead  is  formed  slowly  on  adding  butyric  acid  to 
lead  acetate  as  a  heavy  liquid  which  solidifies  on  standing. 
Alkaline  butyrates,  with  lead  acetate  in  moderately  concentrated 
solution,  give  a  milky  precipitate,  which  afterward  solidifies  in 


VALERIC  ACID. 

a  white  semi-crystalline  mass.  A  nearly  saturated  solution  of 
butyrate  of  lead,  left  over  sulphuric  acid,  deposits  fine,  silky 
needles  which  are  anhydrous.  Butyrate  of  silver  is  formed  in 
shining  scales  by  mixing  moderately  dilute  solutions  of  nitrate 
of  silver  and  alkaline  butyrate.  Butyrate  of  copper  forms  blue-  - 
green  monoclinic  crystals  sparingly  soluble  in  water  (see  Valeric 
acid,  b).  Butyrate  of  zinc  crystallizes  in  shining  scales.  Buty- 
rate of  barium  is  formed  by  saturating  butyric  acid  with 
hydrate  of  barium,  and  crystallizes  in  the  cold  in  long  flattened 
prisms  containing  2  aq.  Butyrate  of  calcium,  obtained  in 
the  same  way,  crystallizes  in  delicate  needles,  anhydrous. — 
Butyrates  of  lead,  barium,  calcium,  potassium,  and  some  other 
metals,  rotate  rapidly  when  dropped  in  small  fragments 
upon  water. 

d.  Butyric  acid  distils  unchanged  at  157°  C.  Its  separation 
from  propionic,  acetic,  valeric,  caproic,  and  other  acids  of  conti- 
guous boiling  points,  is  best  accomplished  by  fractional  saturation 
and  distillation.  (43.  Also,  see  Valeric  acid,  c.) 

Quantitative. — e.  Butyric  acid  has  been  determined  by 
saturation  with  (10  parts  of  dry)  bismuth,  hydrate,  and  precipi- 
tation of  the  butyrate  of  bismuth  with  ammonia  to  obtain  the 
oxide  of  bismuth,  which  is  dried  and  weighed.  Bi2O3  :  6H 
C4H702  :  :  1  :  1.1282. 

42.  VALERIC  ACID.  HC5H9O2.  Identified  by  its  odor 
and  taste,  tho  odor  of  its  ethers,  and  the  taste  of  its  alkaline 
salts  (a) ;  by  its  consistence,  boiling  point,  solubilities,  and  the 
properties  of  certain  of  its  metallic  salts  (b). — Separated  by 
fractional  distillation  (c) ;  by  solubility  of  certain  salts  of  lead, 
copper,  iron,  barium,  zinc  (d). — Determined  by  acidimetry  (e)  ,- 
approximately,  by  solubility  in  water  (f). 

a.  The  odor  of  valeric  acid  is  that  characteristic  of  dried 
valerian  root  and  of  common  valerian  oil,  in  part  like  that  of 
decayed  cheese  and  also  of  butyric  acid.  When  not  diluted,  it 
has  a  sour,  burning,  and  disagreeable  taste  and  caustic  effect. 


64  LIQUID  VOLATILE  ACIDS. 

The  alkaline  vdlerates  have  a  sweetish  taste,  with  a  pungent  and 
alkaline  after-taste,  and  when  moist  exhale  some  odor  of  valeric 
acid.  Etliyl  valerate,  evolved  on  warming  valeric  acid  or  its 
salts  with  alcohol  and  sulphuric  acid,  has  an  agreeable,  fruity 
odor.  Amyl  valerate,  formed  by  heating  valerianic  acid  with  a 
very  little  fusel-oil  and  sulphuric  acid,  is  characterized  by  a 
pleasant  apple  odor. 

1).  Absolute  valeric  acid  ("  monohydrate ")  is  a  transparent 
and  mobile  oily  liquid,  of  sp.  gr.  of  .937  at  15°  C.,  boiling  at 
175°  C.  With  water  it  forms  a  definite  hydrate — HC5H9O2 . 
H2O  ("  trihydrate  ") — an  oily  liquid  of  sp.  gr.  of  .950,  boiling  at 
165°  C.,  but  gradually  dehydrated  by  distillation,  the  first  dis- 
tilled portion  containing  the  hydrate  mixed  with  water,  after 
which  the  absolute  acid  passes  over. — Absolute  valeric  acid  is 
soluble  in  30  parts  of  water  at  ordinary  temperatures;  the 
hydrated  acid  in  26  parts.  It  is  almost  wholly  removed  from 
solution  by  saturation  with  freely  soluble  salts,  as  chloride  of 
calcium  or  of  sodium.  It  is  soluble  in  all  proportions  of  alcohol, 
ether,  chloroform,  and  glacial  acetic  acid. 

The  valerates  of  the  alkali  metals  are  deliquescent  and  freely 
soluble  in  water  and  in  alcohol ;  of  the  alkaline  earth  metals, 
moderately  soluble  in  water  and  in  aqueous  alcohol.  Aluminum 
valerate  is  insoluble.  Ferric  valerate  (basic)  insoluble.  Zinc 
valerate  is  soluble  in  90  parts  of  water,  and  in  60  parts  of 
alcohol  of  80  per  cent.  Bismuth  valerate  (basic)  insoluble  in 
water ;  silver  valerate,  slightly  soluble  in  water ;  lead  valerate 
(normal)  readily  soluble  in  water,  (basic)  sparingly  soluble  in 
water;  mercuric  valerate,  soluble;  mercurous,  slightly  soluble; 
cupric  valerate,  moderately  soluble. 

The  lead  valerate  crystallizes  in  shining  needles  gathered  in 
hemispherical  groups ;  silver  valerate  in  white,  shining  plates ; 
copper  valerate  in  green-blue  monoclinic  prisms ;  mercury  vale- 
rate  in  slender  white  needles  ;  zinc  valerate  in  snow-white  plates 
of  pearly  lustre.  The  sodium  and  potassium  valerates  melt  at 
140°  C.,  and  solidify  in  amorphous  cakes,  white  when  pure. 


VALERIC  ACID.  65 

Sodium  valerate  crystallizes,  by  spontaneous  evaporation  in 
warm  and  dry  air,  in  cauliflower-shaped  masses. — Many  of  the 
valerates  rotate  upon  the  surface  of  water  when  dropped  in 
small  fragments  upon  it. 

Silver  valerate  is  precipitated  from  solutions  of  valerates 
not  too  dilute  in  a  white  curd,  turning  black  in  the  light. — 
Solution  of  acetate  of  copper  on  agitation  with  concentrated 
valeric  acid  forms  anhydrous  valerate  of  copper  in  oily  droplets, 
which,  after  five  to  twenty  minutes,  crystallize  as  greenish-blue 
monoclinic  prisms  or  octahedrons  of  hyd rated  cupric  valerate, 
soluble  in  a  moderate  quantity  of  water  and  in  alcohol.  (Dis- 
tinction from  Butyric  acid,  which  forms  in  solution  of  acetate 
of  copper,  not  very  dilute,  an  immediate  precipitate  or  turbidity 
of  butyrate  of  copper,  bluish-green  and  finely  crystalline  in 
monoclinic  prisms — LOROCQUE  and  HURAUT.) — Valerates  are  de- 
composed by  acetic,  tartaric,  citric,  and  malic  acids ;  not  by 
butyric  acid. — Valeric  acid  decolors  potassium  permanganate 
solution. 

c.  Valeric   acid    is    easily   separated    from  Butyric  acid  by 
fractional  saturation  and  distillation  of  the  latter,  the  butyrate 
being  wholly  decomposed  at  the  temperature  of  the  less  volatile 
acid,  which   remains   in  the  retort  as  valerate  (41,  d).     With 
Acetic  acid,  however,  the  more  volatile  acid  is  held  by  the  base 
in  the  retort,  while  valeric  acid'  distils  over.     In  decomposing 
valerates  for  distillation  of  the  acid,  sulphuric  acid  may  be  em- 
ployed, avoiding  a  strong  excess. 

d.  Valeric  acid  is  separated  from  acids  which  form  insoluble 
lead  salts  by  the  method  given  under  Acetic  acid,  g.     From 
acids  forming  soluble  salts  of  aluminum,  by  the  insolubility  of 
aluminum  valerate. — If  a  solution  of  a  valerate  made   slightly 
alkaline  to  test-paper  is  fully  decomposed  by  solution  of  ferric 
chloride,  and  after  a  short  time  filtered,  the  filtrate  will  be  red  if 
Acetic  acid  is  present.     "  A  solution  of  valeric  acid  in  50  parts 
of  hot  water,  saturated  with  hydrated  carbonate  of  zinc,  yields  a 
liquid   which,    when   filtered   and    evaporated   to   10  parts  and 


66  LIQUID    VOLATILE  ACIDS. 

cooled,  affords  white  pearly  crystals  of  valerate  of  zinc.  The 
mother- water,  drained  from  these  crystals,  should  not  yield,  by 
further  evaporation  and  cooling,  a  salt  crystallizing  in  six-sided 
tables  and  very  soluble  in  water"  (acetate). — Valerate  of  barium 
is  soluble  in  2  parts  cold  water,  sparingly  soluble  in  alcohol ; 
Caprylate  of  barium  in  120  parts  water,  nearly  insoluble  in 
alcohol ;  Caprinate  of  barium  almost  insoluble  in  water. 

Quantitative. — e.  Free  valeric  acid,  in  absence  of  other 
acids,  may  be  determined  by  normal  volumetric  solution  of  alkali. 
Weighing  10.2,  the  number  of  cub.  cent,  of  alkali  solution  equals 
the  number  per  cent,  of  HC5H9O2 ;  weighing  12.,  the  number  of 
cub.  cent,  equals  the  number  per  cent,  of  HC5H9O2.H2O. 

f.  A  weighed  quantity  of  the  acid  (1  gram  in  a  tared  flask) 
should  require  not  less  than  26  times  its  weight  of  water  at  16° 
to  18°  C.  for  perfect  solution  (absence  of  alcohol,  acetic  acid, 
valerates,  etc.),  and  should  require  not  more  than  30  times  its 
weight  for  exact  solution  (absence  of  fatty  acids,  valeral,  etc.) — 
DUFLOS. 

43.  Formic,  Acetic,  Butyric,  and  Valeric  acids  may  be 
separated  from  each  other  by  Fractional  Saturation  and 
Distillation,  as  follows  :  (This  method  is  generally  applicable 
in  fractional  distillation.) — To  one-half  of  the  material  to  be 
distilled  add  enough  potassa  or  soda  to  neutralize,  and  then  mix 
with  the  other  half  and  distil — with  a  thermometer  in  the  retort 
or  generating  flask  to  show  the  boiling  point — receiving  the  dis- 
tillate all  together.  If  the  boiling  point  has  been  constant,  no 
farther  separation  can  be  effected  by  this  method ;  if  not,  saturate 
half  the  distillate,  mix  with  the  remainder,  and  distil  as  before. 
Repeat  the  fractional  saturation  with  alkali  and  distillation  of 
the  free  acid  of  the  receiver  until  the  distillate  has  a  constant 
boiling  point.  Now  to  the  several  retort  residues  add  excess  of 
dilute  sulphuric  acid  and  distil  each ;  if  their  distillates  do  not 
show  a  constant  boiling  point,  half  saturate  and  distil,  in  each 
case,  as  before,  until  the  boiling  points  are  constant.  Again 


VOLATILE    FAT  ACIDS. 


07 


decompose  and  distil  the  retort  residues,  as  before,  repeating  the 
operations  until  the  whole  of  the  organic  acids  is  obtained  in 
separate  distillates,  each  showing  a  constant  boiling  point.  The 
work  may  be  tabulated  as  follows : 


Fractional  Saturation  and  Distillation. 


Mixture  of  acids,  a,  6,  c,  d,  of  different  boiling  points. 
Neutralize  half  the  mixed  acids  and  distil. 


IN  RETORT  :  salts  of  c,  d. 
Saturate  with  sulphuric  acid  and 

distil. 

(Boil,  point  changes.) 
Neutralize  half  and  distil. 


IN  RECEIVER  :  a,  6  (boil,  point 

changes). 
Neutralize  half  and  distil. 


IN  RETORT  :  salt  IN  RECEIVER  :  c. 
of  d. 

Saturate  with  sul-  (Boil.pt.  const'nt.) 
phuric  acid  and 
distil. 

IN  RECEIVER  :  d. 
(Boil.pt.  const'nt.) 


IN  RETORT  :  salt 
of  6. 

Saturate  with  sul- 
phuric acid  and 
distil. 

IN  RECEIVER:  b. 
(Boil.  pt.  const'nt.) 


IN  RECEIVER  :  a. 
(Boil.  pt.  const.) 


44.    VOLATILE   FAT   ACIDS   of   the   Acetic   Series. 

(Approaching  towards  these,  in  their  properties,  are  the  volatile 
acids  of  the  acetic  series  which  do  not  have  a  fatty  consistence, 
though  commonly  termed  "  volatile  fatty  acids  " — viz.,  FORMIC, 
ACETIC  [PROPYLIC],  BUTYRIC,  and  VALERIANIC  acids.) 
CAPROIC  ACID,  HC6  HalO2,  boil,  at  200°C.,  melt,  at  9°C. 
(ENANTHYC  ACID,  HC7  H13O2,  "  "  218°C.,  "  below  20°C. 
CAPRYLIC  ACID,  HC8  H15Qa,  "  "  236°C.,  «  at  15°C. 
PELARGONIC  ACID,  HC9  H17Oa,  "  "  260°C.,  "  "  10°C. 
CAPRIC  ACID,  HC10H19O2,  "  with  decom.,  "  "  30°C. 

Characterized  by  their  pungent  and  unpleasant  odors  (when 
free),  by  the  persistent  and  fragrant  odors  of  their  ethyl  ethers, 
by  their  liquid  and  more  or  less  oily  consistence  at  ordinary 
temperatures  and  their  capability  of  distillation,  by  their  sparing 


08  FAT  ACIDS,    LIQUID   AND   SOLID. 

solubility  or  insolubility  in  water  and  ready  solubility  in  alcohol 
and  in  ether,  by  their  acid  reaction,  by  forming  with  alkalies 
salts  soluble  in  water. 

Separated  from  each  other  by  Fractional  Crystallization, 
as  barium  salts,  as  follows :  Add  to  the  mixture  (aqueous  or 
alcoholic)  sufficient  potassa  to  neutralize,  and  add  chloride  of 
barium  to  decompose.  Crystallize,  removing  the  successive 
crops  of  crystals : 


FROM  WATER  SOLUTION. 

1st  crop — baric  caprate, 
2d     "  "     pelargonate, 

3d     "  *'     caprylate, 

4th    "  "     oenanthate, 

5th    "  "     caproate. 


FROM  ALCOHOL  SOLUTION. 

1st  crop— baric  caprylate, 
2d     "  "     oenanthate, 

3d     "  "     pelargonate, 

and  caprate, 
4th    "  "     caproate. 


The  aqueous  crystal-crops  may  be  washed  with  hot  alcohol — 
the  washings  containing  the  salts,  successively,  in  order  the 
reverse  of  their  crystallization  from  alcohol.  Thus,  the  third 
crop  of  crystals  from  water,  when  washed  with  alcohol,  lose  first 
caproate,  then  caprate  and  pelargonate,  lastly  cenanthate,  with 
little  loss  of  caprylate. 

Separated,  also,  by  Fractional  Saturation  (43). 


FAT    ACIDS,  LIQUID    AND   SOLID. 

45.  NON-VOLATILE  FAT  ACIDS.  Characterized  by 
an  oily  consistence,  leaving  a  permanent  oil-spot  upon  paper, 
and  melting  at  different  temperatures,  mostly  between  14°  C.  and 
80°  C. ;  by  insolubility  in  water,  upon  which  they  mostly  float 
(in  oily  drops  or  layers,  liquid  if  the  water  is  hot) ;  by  free  solu- 
bility in  alcohol,  the  solutions  mostly  having  an  acid  reaction, 
and  by  solubility  in  ether ;  by  the  (soapy)  solubility  of  their 


NON-VOLATILE  FAT  ACIDS.  69 

alkaline  salts  in  water ;  by  the  waxy  consistence  of  their  lead 
salts,  which  melt  and  do  not  dissolve  in  water  and  have  differing 
solubilities  in  alcohol  and  ether  ;  by  forming  white,  milky  preci- 
pitates when  their  alkaline  salts  in  water  solution  are  treated 
Vvith  salts  of  metals  not  alkalies,  or  with  acids,  also  when  (as  free 
acids)  their  alcohol  solutions  are  diluted  with  water.  The  avi- 
dity of  drying  oils  for  oxygen  is  a  characteristic  of  their  acids. 
(See  Fixed  Oils.) 

The  nine  following  are  some  of  the  more  frequently  occurring 
non-volatile  fat  acids,  placed  in  order  of  their  fusibility  : 

46.  RICINOLEIC  ACID.     HC18H33O3.     Melts  at  10°  to  6°  C. 
(14°  to  21°  F.).     Yellowish,  syrupy,  inodorous,  of  harsh  and  per- 
sistent taste ;  reddens  litmus,  and  in  alcoholic  solution  decom- 
poses carbonates    with   effervescence ;    distils    an   illy-smelling 
liquid  ;  its  glyceride  and  all  its  metallic  salts  soluble  in  alcohol, 
its  lead  salt  soluble  in  ether.     When  Castor  Oil  (ricinoleate  of 
glyceryl)  is  heated  on  a  sand-bath  with  a  double  volume  of  nitric 
acid  of  25  per  cent.,  until  the  nitric  acid  is  allremoved^  the  resi- 
due saturated  with  concentrated  solution  of  sodium  carbonate — 
the  characteristic  odor  of  oenanthyc  acid  is  obtained. 

47.  OLEIC  ACID.     HC18H33Oa.     Melts   at   14°  C.  (57°  F.), 
soft  above  4°  C.  (39°  F.)       Colorless,  limpid  liquid  of  sp.  gr. 
0.808,  odorless  and  tasteless,  crystallizing   from  cold  alcoholic 
solution  in  white  needles ;  reaction  neutral,  becoming  acid  on 
exposure  to  the  air,  by  which  it  finally  turns  brown  and  rancid. 
Its  lead  salt  (lead  plaster)  is  insoluble  in  alcohol,  slowly  soluble 
in  ether  (separation  from  palmitate,  stearate,  laurate,  etc.)     Dis- 
tilled with  nitric  acid,  all  the  volatile  acids  of  the  acetic  series  are 
found  in  the  distillate. 

48.  LINOLEIC   ACID.     H  C16H27Oa  ?     Melts  at  about  18°  C. 
(64°  F.) ;  faint  yellow,  limpid  liquid  of  sp.  gr.  0.921,  of  taste  at 
first  mild  and  afterward  harsh  ;  faintly  acid  to  test-paper  ;  oxid- 
izes in  the  air  to  a  thick,  viscid  mass,  its  salts,  also,  being  changed 
in  the  air.      Most  of  the  linoleates  are  soluble  ia  alcohol ;  the 
lead  salt  is  soluble  in  ether. 


70  FAT  ACIDS,  LIQUID  AND  SOLID. 

49.  ERTJCIC  ACID.      C20H42O2.      Melts  at   34°  C.  (94°  F.) ; 
crystallizes  from  alcohol  in  shining  needles  ;  lead  salt  not  soluble 
in  ether  (separation  from  Oleic  acid) . 

50.  LAURIC  ACID.     HC12H23O2.    Melts  at  43°  C.  (110°  F.) ; 
solidifies  in  scales  and  crystallizes  from  alcohol  in  white  needles ; 
slightly  acid  to  test-paper ;  lead  salt  sparingly  soluble  in  alcohol, 
insoluble  in  ether. 

51.  MYRISTIC  ACID.     HC14H27O,.     Melts  at   54°  C.   (129° 
F.) ;  crystallizes  in  shining  laminae ;  exceptional  in  being  insolu- 
ble in  ether ;  the  alcoholic  solution  has  an  acid  reaction ;  the  lead 
salt  is  soluble  in  alcohol,  but  insoluble  in  ether ;  the  barium  salt 
nearly  insoluble  in  alcohol. 

52.  PALMITIC  ACID.    H  C16H31Oa.    Melts  at  62°  C.  (143°  F.) ; 
colorless,  tasteless,  odorless,  showing  an  acid  reaction ;  lighter 
than  water ;  crystallizes,  in  congealing,  in  shining  scales,  from 
dilute  solutions  in  slender  needles ;  lead  salt  insoluble  in  alcohol 
or  cold  ether ;  barium  salt  sparingly  soluble  in  water  or  alcohol ; 
calcium  salt  insoluble  in  water  or  ether,  slightly  soluble  in  warm 
alcohol. 

53.  STEARIC  ACID.    H  C18H35Q2.    Melts  at  70°  C.  (159°  F.) ; 
inodorous,  tasteless,  colorless  in  liquid  and  white  in  solid  state ; 
crystallizes  from  alcohol  in  needles  or  nacreous  scales,  having  the 
specific  gravity  of  water ;  its  solutions  distinctly  acid  to  test- 
paper  ;  lead  salt  insoluble  in  alcohol  or  ether,  and  not  wetted  by 
water  and  fusible  at  125°  C. ;  barium   salt  insoluble  in  water, 
alcohol,  or  ether ;  magnesium  salt  insoluble  in  water,  and  slightly 
soluble  in  cold,  more  soluble  in  hot  alcohol.     [For  the  fusing- 
points  and  modes  of  solidification  of  mixtures  of  Stearic  with 
Laurie,  Myristic,  and  Palmitic  acids,  as   determined  by  HEINTZ, 
see  Watts's  Dictionary  ^  v.,  414.] 

54.  CEROTIC  ACID.     H.C27H53Oa.    Melts  at  79°  C.  (174°  F.) ; 
crystallizes  in  congealing  in  small  grains,  lighter  than  water; 
when  pure,  is  capable  of  distillation ;  soluble  in  hot  alcohol  and 
in  ether,  not  soluble  in  chloroform ;  solutions  acid  in  reaction : 
lead  salt  insoluble  in  alcohol. 


NON-VOLATILE  FAT  ACIDS.  71 

55.  The  non-volatile  Fat  Acids  are  separated  from  neutral 
fats  by  saponification  with  fixed  alkalies,  lime,  or  oxide  of  lead, 
in   each    case    effected  by  hot   digestion  in  presence  of  water. 
Sometimes  an  alcoholic  solution  of  alkaline  salt  is  precipitated  by 
alcoholic  acetate  of  lead  (the  lead  salt  being  insoluble  in  alcohol) ; 
in  other  cases,  an  alcoholic  solution  of  lead  salt  is  precipitated  by 
alcoholic  acetate  of  barium  or  of  magnesium   (such  being  the 
solubilities  of  the  respective  salts).      Then  the  purified  salt  is 
decomposed  in  water  with  dilute  acid. 

As  in  manufacturing  operations,  the  neutral  fats  may  be 
decomposed  by  superheated  steam,  with  separation  of  the  fat 
acids  together. 

56.  The  fat  acids  are  in  some  cases  separated  from  each 
other  by  fractional  fusion  of  their  glycerides,  with  pressure. 
The  melting  point  of  the  glycerides  (the  neutral  fats),  is  given  in 
59.     The  melting  point  of  a  mixture  of  free  fatty  acids  is  gene- 
rally much  below  the  mean  melting  point  of  its  constituents,  as 
shown  by  the  tables  of  Heintz  mentioned  in  54,  and  Alienee  in 
many  cases  no  separation   can   be   accomplished  by  fractional 
fusion.     Thus,  free  stearic  acid  can  be  freed  from  oleic  but  not 
from  lauric,  myristic,  or  palmitic  acid,  by  this  process. 

57.  The  use  of  solvents  in  separation — of  the  free  acids  or  of 
their  salts — is  indicated  to  some  extent  by  the  statements  of  solu- 
bilities, given  in  this  work  or  elsewhere,  and  more  particularly 
by  the  various  methods  of  preparation  of  the  acids  in  question, 
as  found  in  Watts'  Dictionary,  Miller's  Organic,  Gmelin's  Hand- 
book, and  in  original  reports. 

Free  fatty  acids  are  separated  from  neutral  Fat  oils  (not 
from  castor  oil),  for  commercial  determinations,  by  extracting 
the  oil  with  one  or  two  volumes  of  90  per  cent,  alcohol.  The 
acid  is  then  determined  volumetrically  with  soda  solution.* 

Also,  by  alkaline  carbonates,  which  at  ordinary  temperatures 
saponify  with  fat  acids  but  not  with  fats.  Prepare  a  solution  of 

*  BTTBSTTN  :  Zeitschr.  Anal.  Chem.,  xi.,  383. 


72  NEUTRAL  SUBSTANCES,   LIQUID    OR  FUSIBLE. 

10  grams  crystallized  sodic  carbonate,  1  gram  sodic  bicarbonate, 
and  30  c.  c.  water.  Agitate,  in  a  test-tube,  equal  volumes  of  this 
solution  and  of  the  oil,  and  set  aside  at  ordinary  temperatures. 
In  absence  of  fat  acids,  the  two  liquids  separate,  more  or  less 
turbid ;  if  fat  acids  are  present,  an  emulsion  is  formed  (from 
which  a  cream  rises  after  some  time).  Old  fat  oils  usually  con- 
tain traces  of  fat-acids,  scarcely  indicated  in  this  test. 

58.  For  the  quantitative  determination  of  free  fat-acid  in 
mixture  with  neutral  fats,  digest  10.0  grams  of  the  oil  with  2.5 
grams  of  pulverized  sodic  bicarbonate  and  25  drops  of  water,  on 
a  water-bath,  with  trituration,  for  an  hour.  When  cold,  extract 
with  petroleum  naphtha,  stirring;  evaporate  the  naphtha,  and 
weigh  the  neutral  fat  so  separated.  Benzole  is  not  applicable  in 
this  separation. 


NEUTRAL   SUBSTANCES,  LIQUID  OR  FUSIBLE. 

59.  FIXED  OILS.  Fats  or  Fat-oils.  Glycerides  of  the 
non- volatile  fat  acids.  (The  following  list  includes  those  of  most 
frequent  occurrence  in  commerce.) 

a.    LIQUID  AT  ORDINARY  TEMPERATURES. 

aa.  DRYING  OILS    (NOT  FORMING  ELAIDIN). 

Spec.  grav.    Congeal,  pt. 

Hemp-seed,  .  .  0.926  -25°  C.,  -13°  F.  Greenish  when  fresh,  afterward 

brownish-yellow ;  unpleasant 
odor  and  insipid  taste. 

Grape-seed,  .  .  .918  -13°  C.,  9°  F.  Yellow  to  brownish  ;  nearly  odor- 
less, of  mild  taste. 

Linseed,  ...  .934  -37°  C.,  -17°  F.  Gold-yellow  to  brownish  ;  strong 

odor  and  taste. 

Poppy-seed,  .  .  .924  -18°  C.,  0°  F.  Straw-yellow  ;  limpid  ;  feebly  plea- 
sant odor  and  taste. 

Walnut,  .  .  .  .925  -18°  C.,  0°  F.  Slightly  greenish  or  yellowish; 

thick  ;  nearly  odorless,  of  mild 
nutty  taste. 


FIXED    OILS.  73 

bb.  OILS  DRYING  TO  A  SLIGHT  EXTENT  AND  SLOWLY  FORMING  A  LITTLE 

ELAIDIN. 

Spec.  grav.     Congeal.pt. 
Beechnut,      .    .  •  .920    -18°  C.,     0°  F.  Yellowish  ;  nearly  odorless  and  of 

a  mild  taste. 
Cotton-seed,.    .      .935       1°C.,    34°  F.  Yello w  or  brownish-yellow  to  color- j 

less  ;  of  mild  taste. 
Croton,      .    .    .      .943       Clear,  slightly  yellow  ;  of  a  taste  at 

first  mild  and  then  burning  and 

persistent ;  causes  pustules  on 

the  skin. 

Sesame,     .     .    .      .931        0°  C.,    33°  F.  Yellow  ;  of  mild  odor  and  taste. 
Sunflower,     .    .      .924    -15°  C.,     5°  F.  Yellowish;  limpid;   nearly  odor- 


CC.    OILS  NOT  DRYING,  BUT  NOT  FORMING  ELAIDIN. 

Cod-liver, ...  .930  below  14°  F.  Clear  yellow  to  red-brown  ;  acid 

reaction ;  characteristic  fishy 
odor  and  taste. 

Whale, 925  0°  C.,  32°  F.  Brownish  ;  of  characteristic  dis- 
agreeable odor  and  taste. 

dd.  NON-DRYING  OILS,  FORMING  ELAIDIN. 

Almond,  .  .  .  .918  -20°  C.,  4°  F.  Clear  straw-yellow ;  limpid ;  in- 
odorous, of  a  bland,  sweetish 
taste. 

Castor, 963  -15°  C.,  5°  F.  Colorless  or  slight  yellow  ;  syrupy; 

odorless,  of  mild  taste  with  acrid 
after-taste.  (Sometimes  classed 
among  the  slightly  drying  oils.) 

Colza, 914     -6°  C.,    31°  F.   Clear,  yellowish  ;  limpid. 

Hazel-nut,      .    .      .920    -19°  C.,    -3°  F. 

Lard, 915  10°  to  0°  C.  Colorless  or  nearly  so  ;  slight  odor 

of  lard. 

Mustard  (black),  .915  15°  C.,  5°  F.  Yellowish  ;  odorless,  of  mild  char- 
acteristic taste. 

Mustard  (white),      .913    (not  solidified).  Similar  to  the  above. 

Neatsfoot,  .  .  —  (below  0°  C.)  Yellowish  ;  inodorous,  of  a  bland 

taste. 

Olive, 916  5°  C.  to  3°  C.  Greenish  or  yellowish  ;  thick  flow- 
ing ;  of  slight  pleasant  or  no 
odor  and  mild  sweetish  taste. 

Sperm,      ...      .875       Limpid ;  nearly  odorless. 

Rape-seed,  .  .  .914  -6°  C.,  31°  F.  Clear,  yellowish  ;  disagreeable  odor 

and  taste. 


74 


NEUTRAL   SUBSTANCES,  LIQUID    OR   FUSIBLE. 


b.    SOLID    AT    ORDINARY    TEMPERATURES. 


Melting. 

Butter, 27°  to  30°  C. 

Cacao  butter,     .    .    .     25°  to  30°  C. 

Lard, 28°  to  32°  C. 

Tallow,  Beef,      ...     36°  to  40°  C. 


Tallow,  Mutton,    m. 
Spermaceti,    .    .    . 
Wax,  Yellow  (Bees'), 
Wax,  White,      .    . 


Melting. 
46°  to  50°  C. 
38°  to  47°  C. 
60°  to  63°  C. 
65°  to  69°  C. 


60.  Fixed  or  Fat  Oils  are  characterized  by  their  oily  con- 
sistence and  the  physical  properties  stated  above  ;  by  their  solu- 
bilities (a)  and  cohesion-figures  on  water  (b) ;  by  a  neutral 
reaction ;  by  saponification — forming  soapy-soluble  compounds 
with  alkalies  and  waxy  compounds  with  lead  oxide  (c) ;  by 
giving  reactions  for  glycerin  (d) ;  by  the  precipitates  obtained 
from  their  soap- solutions  (e) ;  by  either  oxidizing  to  a  viscid 
mass  in  the  air  (f),  or  forming  elaidin  with  nitric  acid  (g) ;  by 
their  sensible  reactions  with  special  reagents  (k). 

a.  Insoluble  in  water,  upon  the  surface  of  which  they  float. 
Mostly  insoluble  or  slightly  soluble  in  alcohol ;  but  Castor  oil  is 
soluble  in  all  proportions  of  absolute  alcohol,  Spermaceti  in  7 
parts  of  boiling  absolute   alcohol,   and  Wax  partly  soluble   in 
alcohol.     Soluble  in  Ether  and  in  Benzole,  less  freely  soluble  in 
petroleum  naphtha  and  in  chloroform.     (Solid  fats  are  slightly 
soluble  in  petroleum  naphtha ;  liquid  fats  moderately  soluble.) 
Miscible  with  volatile  oils,  not  with  glycerin. 

By  violent  agitation  with  water,  fixed  oils  form  milky  mix- 
tures (emulsions)  from  which  the  oil  quickly  separates  in  drops ; 
by  agitation  or  trituration  with  water  mucilages  of  gums,  albu- 
men, gelatin,  sugar,  and  of  salts,  more  perfect  mixtures  are 
formed,  from  which  the  oil  slowly  separates  as  a  cream,  still 
containing  a  little  water  solution  and  holding  the  oil  in  its  charac- 
teristic microscopic  spheres. 

b.  If  a  drop  of  oil  is  let  fall  upon  a  still  surface  of  perfectly 
pure  water,  the  oil  spreads  in  a  film  which  breaks -into  a  figure 
(cohesion  figure)  or  succession  of  figures,  characteristic  of  each 
oil — fixed  oils  not  being  distinguished  from  volatile  oils  other- 
wise than  from  each  other.     The  formation  of  these  figures  con- 


FIXED    OILS.  75 

stitutes  a  practicable  means  of  identifying  the  separate  oils,  and 
even  to  some  extent  of  recognizing  them  when  in  mixture.* 

c.  8aponification  is  effected  in  presence  of  water  by  digesting 
with  excess  of  alkali  for  some  time,  or  with  oxide  of  lead  at 
100°  C.  for  a  longer  time.  The  alkali-soaps  dissolve  in  water, 
the  solution  being  slightly  milky,  and  becoming  more  turbid  on 
dilution,  and  dissolve  in  alcohol,  but  mostly  refuse  to  dissolve  in 
ether.  The  lead  soaps  of  some  of  the  fat  acids  are  soluble  in 
ether ;  they  are  fusible,  waxy  compounds.  See  Non-volatile  Fat 
Acids  (45). 

d.  The  glycerin  formed  in  saponrfication  with  oxide  of  lead 
or  with  lime,  as  above,  when  separated  by  the  concentration  of 
the  clear  water  solution,   renders  evidence  of  its   identity,  by 
means  of  tests  given  under  the  head  of  glycerin  (66). 

e.  The  alkali-soap  solutions  give  white  precipitates  with  solu- 
tions of  salts  of  metals  not  alkaline,  and  with  acids  give  white 
precipitates  soluble  in  alcohol. 

f.  THE  DRYING  OILS  are  recognized  by  not  forming  elaidin, 
when  treated  as  stated  in  the  next  paragraph ;  by  drying  to  a 
resinous  film  when  spread  and  exposed  to  the  air,  and  by  induc- 
ing elevation  of  temperature,  and  in  many   instances  ignition, 
when  diffused  through  a  mass  of  wool  or  other  porous  material 
and  exposed  to  the  air. 

g.  THE  NON-DRYING  OR  ELAIDIN-FORMING  OILS  are  known  by 
reaction  with  peroxide  of  nitrogen.     A  concentrated  solution  of 
mercuric  nitrate,  or  nitric  acid  of  brown-red  color,  may  be  used. 
For  the  reactions  given  in  the  following  table,-)-  a  little  of  the  oil 
is  taken  in  a  test-tube,  an  equal  volume  of  nitric  acid  of  about 
25  per  cent,  is   added,  the  test-tube  briefly  shaken,  a  strip  of 
copper  turnings  added,  and  the  whole  set  aside  at  ordinary  warm 
temperature,  to  be  examined  each  quarter  of  an  hour. 


*  TOMLINSON,    MOFFAT  :    Chem.    News,    1869.     CRANE  :    Am.   Jour. 
Phar.,  1874,  Sept. 

t  HAGER'S  Untersuchungen,  ii.,  506. 


76  NEUTRAL   SUBSTANCES,   LIQUID    OR  FUSIBLE. 

Tests  for  Elaidin. 


Oils. 

Result  after  %  to  2  hours. 

Result  after  standing  8  hours  to 
2  days. 

Non-drying  Oils. 

Almond  : 

From  sweet  al- 

White ;  cloudy. 

White  or  whitish  mass,  granu- 

monds. 

lar  after  shaking.     Appears 

From  bitter  al- 
monds. 

White     or     yellowish- 
white  ;   more  or  less 

homogeneous  after  8  to  12  hrs. 
Yellowish  ;  only  partly  solidi- 
fied, with  a  surface  layer  of 

Bone,     .... 

turbid. 
Whitish-yeUow. 

semi-liquid,  transparent  oil. 
Nearly  all  solid  ;  a  clear-yellow 
oillayen  with  a  whitish  crys- 
talline finely  granular  preci- 

pitate. 

Castor,  .... 

Whitish. 

Whitish;    solidifying    after   8 

hours  or  earlier. 

Lard,     .... 

Whitish-yellow. 

Whitish  or  yellow-  white  ;  some- 

what granular,  with  transpa- 

rent spots  ;  rigid  ;  sometimes 

with    a    half-liquid    surface 

Olive: 

layer. 

Green,      .    .    . 

White  cloudiness,  often 

White     or      yellowish  -brown- 

modified  by  color  of 

white  solid,    made   granular 

the  oil. 

by  shaking.      The   mass  ap- 

pears uniform  after  4  to  8  hrs. 

Yellow,   .    .    . 

White  or  whitish  cloud- 

White or  yellowish-  white  mass, 

iness. 

granular  after  shaking.     Af- 

ter 4  to  8  hours  the  surface 

Rape-seed  : 

appears  nearly  uniform. 

Crude,     .    .    . 

Yellow-brown    to   red- 
brown. 

Reddish-yellow  ;  solidifying  af- 
ter 16  to  34  hours  and  becom- 

ing brownish-yellow  ;  some- 

what granular  after  shaking, 

the  granules  enclosed  in  an 

oil  layer. 

Refined,  .    .    . 

Whitish-yel'w  to  br'wn- 

Reddish-yellow  ;  solidifying  af- 

yellow. 

ter  16  to  34  hours  and  becom- 

Oils drying  im- 
perfectly. 

ing  yellow  ;  made  granular  or 
pasty  by    shaking,    the  gra- 

nules oil-coated. 

Beech-nut,     .    . 

YeUow  or  reddish-yel- 
low. 

Syrupy;  nearly  clear;  after  2 
days  a  just  perceptible  EC  fa- 
ration  of  elaidin. 

Cotton-seed,  .     . 

Reddish-yel'w  or  br'wn- 
ish. 

Pasty  or   syrupy  ;     frequently 
showing  a  clear  brown-yellow 
oil  layer  of  one-half  to  ore- 

third  the  mixture.    Appear- 
ance of  aprecipt.  after  1  day. 

Sesame,     .    .    . 

Red  to  dark  red. 

Blackish  yellow  -brown  or  red- 

brown  ;  opaque  ;  pasty.    Af- 

ter 1  day  a  transparent  oil 

layer  sometimes  appears  at 

bottom  or  top. 

FIXED   OILS. 

Tests  for  Elaidin — Continued. 


77 


Oils. 

Result  afteip  X  to  2  hours. 

Result  after  standing  8  hours  to 
2  days. 

Sunflower,     .    . 
Drying  Oils. 

Yellowish    or     faintly 
reddish. 

Brownish  yellow.    Pasty  after 
1  day. 

Hemp-seed,    .    . 
Linseed,     .    .    . 
Poppy-seed,   .    . 

Walnut,     .    .    . 

Green. 
Scarcely  changed. 
Scarcely  changed. 

Scarcely  changed. 

Yellow  ;  liquid,  nearly  or  quite 
clear. 
Reddish-brown  ;    liquid      and 
transparent. 
Reddish  yellow-brown  or  red- 
dish    yellow  ;    transparent, 
liquid. 
Yellow  ;  clear  liquid. 

Non-drying  Oils 
not  forming 
Elaidin. 

Cod-liver,      .    . 
Croton,      .    .     . 

Not  changed. 

Unchanged     or     made 
clearer. 

Yellowish-red  or  reddish-br'n  ; 
liquid  and  transparent. 
Thick  liquid  ;  clear. 

If  drying  are  mixed  with  non-drying  oils,  the  latter  are 
easily  detected ;  the  former  only  with  greater  care.  The  elaidin 
mass  remains  partly  liquid,  or  an  oily  layer  separates  from  it.  To 
detect  an  intermixture  of  drying  oil,  proceed  (with  a  weighed 
quantity)  as  above  directed,  leaving  the  mixture  about  two  days, 
then  set  it  aside  at  22°  to  25°  C.  (72°  to  77°  F.)  for  12  hours, 
and  return  it,  without  agitation,  to  ordinary  temperature.  The 
drying  oil  will  now  be  found  more  or  less  perfectly  separated 
from  the  elaidin.  (For  finding  the  proportion  of  the  drying  oil, 
bring  a  tared  roll  of  blotting  paper  into  contact  with  the  mass, 
while  the  temperature  is  8°  to  10°  C.  [46°  to  50°  F.]  The  in- 
crease in  the  weight  of  the  paper  or  the  loss  in  the  weight  of 
the  mixture  approximates  the  weight  of  the  drying  oil.) 

A.  Sulphuric  acid,  Nitric  acid,  Phosphoric  acid,  caustic 
Alkali,  and  Nitrate  of  Silver  are  the  chief  of  the  special  reagents 
for  color-tests  of  fixed  oils. 

The  test  by  sulphuric  acid  is  applied  as  follows :  About  8 
drops  of  the  oil  are  placed  in  a  watch-glass  over  white  paper, 


78 


NEUTRAL   SUBSTANCES,   LIQUID    OR  FUSIBLE. 


and  then  2  drops  of  sulphuric  acid  of  specific  gravity  of  1.820 
to  1.830  (not  more  concentrated)  are  dropped  near  the  edge  of 
the  glass  so  as  to  flow  upon  the  oil.  The  results  are  tabulated 
below ; 

Sulphuric  Acid  Test. 


OIL. 

WITHOUT    STIRRING. 

AFTER  A  LITTLE  STIRRING. 

Almond, 
Castor, 
Cod-liver, 

Lard,    . 
Linseed, 
Olive,  . 
Poppy-^eed, 
Rape-seed:  Crude 
Refined 
Whale, 

Clear  ;  yellow. 
A  tinge  of  pale  brown. 
First  violet,  then  red. 

Brownish  yellow. 
Brown-red. 
Yellow. 
Yellow. 
Greenish-blue. 
Brownish-yellow. 
Red,  afterward  violet. 

Blackish-yellow. 
Faintly  blackish  brown.  • 
Brown-red,   with    violet    rim, 
finally  dark  brown. 
Brown. 
Black-brown. 
Blackish-brown. 
Brownish  olive-green. 
Greenish-blue. 

Brown-red  to  dark  brown. 

61.  Preparation  and  Application  of  Reagents  for  Iden- 
tification of  Fixed  Oils,  according  to  the  following  table 
[CALVERT]  :* 

(1)  Soda  solution.     Specific  gravity  1.33.     4  parts  of  dry- 
soda  in  6  to  7  parts  of  water.     One  volume  of  this  solution 
agitated  with  4  to  5  volumes  of  the  oil  and  heated  to  boiling. 
(The  drying  oils,  so  treated,  form  soft  soaps ;  the  non-drying 
oils,  mostly  hard  soaps.) 

(2)  Sulphuric  acid  of  spec.  grav.  1.475.     Mixture  of  10  parts 
of  the  acid  of  spec.  grav.  1.840  and  7  parts  of  distilled  water. 
One  volume  is  mixed  with  5  volumes  of  the  oil  and  set  aside  for 
ten  minutes. 

(3)  Sulphuric  acid  of  spec.  grav.  1.530.     Mixture  of  10  parts 
of  acid  of  1.840  and  6  parts  of  water.     Mix  1   volume  with  5 
volumes  of  the  oil  and  set  aside  for  five  minutes. 


*  Phar.  Jour.,  xiii.,  356. 


FIXED    OILS. 

(4)  Sulphuric  acid  of  spec.  grav.  1.635.     Mixture  of  10  parts 
of  acid  of  1.840  and  4  parts  of  water.     Applied  like  reagent  (3). 

(5)  Nitric  acid  of  spec.  grav.  1.180.     Mix  1  volume  with  5 
volumes  of  the  oil  and  set  aside  five  minutes. 

(6)  Nitric  acid  of  spec.  grav.  1.220.     Applied  as  directed  for 
reagent  (5). 

(7)  Nitric  acid  of  spec.  grav.  1.330.       Applied  as  directed 
for  (5)  and  results  noted;  then  an   excess  of  the  soda  solution 
(1)  is  added  and  results  noted  again. 

(8)  Phosphoric  acid  of  syrupy  consistence. 

(9)  Sulphuric  acid  of  spec.  grav.  1.840  with  equal  measure 
of  Nitric  acid  of  spec.  grav.  1.330.     One  volume  of  the  mixed 
acids  for  5  volumes  of  oil. 

(10)  Nitrohydrochloric  acid — from  1  volume  of  nitric  acid 
of  spec.  grav.  1.330  and  25  volumes  of  hydrochloric  acid.     One 
volume  of  the  mixture  to  5  volumes  of  oil,  noting  the  result. 
Then  add  excess  of  Soda  solution  (1),  and  again  note  the  result. 


80 


NEUTRAL   SUBSTANCES,   LIQUID    OR   FUSIBLE. 


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EXAMINATION  OF 

>        . 

62.  TESTS  WITH  Nitrate  of  Silver.  A  two  per  cent,  alcoholic 
solution  of  nitrate  of  silver  is  prepared  :  0.5  gram  of  crystallized 
silver  nitrate  being  dissolved  in  1.0  gram  water  and  mixed  with 
25  c.  c.  of  absolute  alcohol.  Now  place  6  or  7  c.  c.  of  the  oil  in 
a  test-tube  about  12  millimetres  (0.47  inch)  thick,  add  2  or  3  c.  c. 
of  the  silver  solution,  shake  briskly  to  form  a  milky  mixture, 
heat,  without  bringing  the  tube  in  contact  with  the  flame,  to 
boiling  for  a  quarter  of  a  minute,  and  set  aside  for  an  hour  or 
two.  A  reduction  of  silver,  with  darkening  of  the  oil  layer 
to  brown,  red-brown,  or  black,  results  from  this  test  with 

Almond  oil,  from  bitter  almonds — colored  after  several  hours. 

Bone  oil — brown  to  black. 

Cotton-seed  oil — brown  to  black. 

Lard  oil. 

Linseed  oil — darkens,  red-brown. 

Rape-seed  oil — brown-red. 

With  the  following  oils  there  is  no  change  : 


Almond  oil, 

from  sweet  almonds, 
Beech-nut  oil, 
Castor  oil, 


Cod-liver  oil, 
Hemp-seed  oil, 
Olive  oil, 
Sesame  oil. 


63.  Special  examination  of  Butter. — Separation  of  fats 
from  non-fatty  substances  by  melting  (a),  by  benzole  (b). 
Identification  of  butyrin,  etc.,  by  etherization  after  saponifica- 
tion  (see  Butyric  acid,  41,  b).  Distinction  from  (mixtures  of) 
lard  by  treatment  with  sulphuric  acid  (c),  by  treatment  with 
ether  at  18.5°  C.  (d),  or  with  petroleum  naphtha  at  10°  to  15°  C. 
(e)  ;  from  foreign  color  by  borax  solution  (f). 

a.  About  10  grams  of  the  butter  are  melted  in  a  large  test- 
tube,  by  insertion  in  water  of  50°  to  60°  C.  (122°  to  140°  F.) 
for  about  an  hour.  The  fats  separate  from  a  subsident  layer  of 
water,  casein,  salt,  lactose,  (foreign  colors).  The  volume  of  the 
latter  may  be  approximately  ascertained  by  linear  measurement 
on  the  tube.  The  fat  layer  from  unsophisticated  butter  is  clear, 


82  NEUTRAL   SUBSTANCES,   LIQUID    OR   FUSIBLE. 

and  has  a  yellow  color  of  a  tint  somewhat  deeper  than  that  of 
the  butter ;  while  the  bottom  layer  is  white,  or  at  most  but  yel- 
lowish-white. (The  bottom  layer  may  be  £  at  most ;  from  good 
table  butter  should  not  be  over  -1.) 

b.  In  a  large  and  strong  test-tube  place  5  grams  of  the  butter, 
melt  by  dipping  in  water  at  60°  C.  (140°  F.),  add  fully  an  equal 
volume  of  benzole,  cork  securely,  agitate,  and  leave  at  about 
40°  C.  (104°  F.)  for  an  hour.     The  sediment  separates  more 
sharply  and  of  thicker  consistence  than  in  a. — The  sediment  may 
be  washed  with  benzole  on  a  filter,  and  analyzed  chemically  and 
microscopically  (see  c,  d,  e). 

For  the  separation  by  benzole,  a  graduated  tube  may  be 
used,  as  follows  (HOORN)  :  A  glass  tube  is  prepared,  20  centi- 
metres (8  inches)  long,  its  upper  two-thirds  having  a  diameter 
of  2  centimetres  (0.8  inch),  its  lower  third  narrowed  and  gradu- 
ated to  tenths  c.  c.,  and  its  lower  end  closed.  In  this  tube  10 
grams  of  butter  are  placed,  melted  by  dipping  in  warm  water ; 
30  c.  c.  of  benzole  are  added,  the  contents  thoroughly  intermixed, 
and  the  tube  set  aside.  After  thirty  to  forty  minutes,  the  ben- 
zole and  fat  will  have  separated  from  the  water  layer  below — the 
amount  of  which  may  be  read  off. 

c.  Take  2  c.  c.  of  the  fats  separated  by  melting  as  in  a,  bring 
the  temperature  to  about  30°  C.  (86°  F.),  add  about  3  c.  c.  of 
concentrated  sulphuric  acid,  and  agitate  gently  to  a  complete 
mixture.     With  butter  alone,  the  liquid  remains  of  a  yellow  be- 
coming yellow-red  color,  clear  and  translucent,  not  darkening  at 
ordinary  temperature,  and  after  half  an  hour  becoming  gelatinous 
and  rather  less  translucent.     If  Tallow  or  Lard  is  present,  the 
mixture  after  a  short  time  becomes  darker,  by  aid  of  the  heat 
generated  by  the  acid,  so  that  after  half  an  hour  it  is  dark  brown- 
red  or  brown-black. 

d.  The  butter  is  melted  over  the  water-bath,  and  after  stand- 
ing the  liquid  fat  is  removed  from  the  subsident  layer.     This  fat 
is  mixed  in  an  evaporating  dish  with  four  or  five  times  its  bulk 
of  hot  water  and  left  two  or  three  hours.     The  solidified  fat  is 


EXAMINATION  OF  BUTTER.  83 

dried  on  blotting-paper,  introduced  into  a  wide-necked  flask,  and 
covered  with  ether  at  a  temperature  of  18.5°  C.  (65.3°  F.)  If 
the  butter  was  pure,  the  fat  fully  dissolves  to  a  clear,  lemon- 
yellow  liquid.  If  the  butter  contained  Lard,  the  fat  is  in  some 
part  insoluble  in  ether  at  this  temperature,  and  the  mixture  is 
left  milky  or  thick,  depositing  a  (finely  granular)  sediment  on 
standing.  Tallow  of  beef  or  mutton  gives  the  same  results,  the 
sediment  being  coarser  than  in  the  case  of  lard.  The  tempera- 
ture of  the  ether  is  the  important  condition  in  this  test,  and  it 
must  not  be  disturbed  by  contact  with  the  hand.  (HORSLEY.)* 
By  special  apparatus,  closer  observations  are  made  with  this 
test  (BALLARD)  as  follows:  Select  a  test-tube  11  or  12  centi- 
metres (4  or  5  inches)  long  and  about  2.5  centimetres  (nearly 
1  inch)  wide;  and  prepare  a  section  of  glass  tubing  of  1.3  to 
1.6  centimetres  (a  little  over  J  inch)  diameter,  and  4  to  5  centi- 
metres (1J  to  2  inches)  long,  each  end  being  slightly  rimmed 
outward,  and  the  one  (lower)  end  bound  over  with  a  bit  of  thin 
canvas.  Weigh  the  little  tube,  with  the  covered  end,  and  place 
in  it  1.5  grams  of  the  butter  to  be  tested,  and  in  the  test-tube 
5  c.  c.  of  ether.  Attach  a  thread  to  the  small  glass  tube  and  let 
it  down  into  the  ether,  then  close  the  test-tube  with  a  cork,  so  as 
to  hold  the  thread,  and  bind  the  cork  over  with  leather.  Im- 
merse the  test-tube  in  water  at  exactly  18.5°  C.  (65.3°  F.)  and 
leave  it  an  hour  at  this  temperature.  The  cap  is  now  removed, 
the  small  tube  drawn  up  out  of  the  ether  by  the  thread  (without 
removing  the  cork),  and  left  at  same  temperature  to  drain.  The 
small  tube  is  now  taken  out,  and  while  the  top  is  closed  by  the 
finger  the  liquid  is  absorbed  as  far  as  possible  by  blotting-paper, 
the  tube  exposed  to  the  air  till  free  from  ether  odor,  and  weighed. 

With  5  c.c.  ether.     With  10  c.c.  ether. 

From  1.5  grams  pure  butter,  remained 

insoluble, 0.18  grms.       0.14  grms. 

From  1.5  grams  beef  tallow,     .     .     .  0.945    " 

From  1.5  grams  lard, 0.9        " 

*  Farther,  see  Chem.  News,  Sept.  11, 1874,  p.  135. 


84  NEUTRAL   SUBSTANCES,    LIQUID    OR   FUSIBLE. 

From  equal  parts  tallow  and  butter,  .    0.6    grms. 
Prom  J-  tallow  and  {  butter,      ...    0.3        «          0.8    grms. 
Prom  1  lard  and  f  butter,     ....    0.15      "          0.8        « 
Prom  |  lard  and  |  butter,     .     .     .     .  0.67     « 

e.  The  fat  of  butter,  separated  according  to  a,  is  treated  with 
7  parts  of  petroleum  naphtha  at  a  low  temperature — 10°  to  15° 
C. — when  the  fat  of  butter  dissolves,  and  tallow,  or  lard  if  over 
10  per  cent.,  remains  in  sediment. 

y.  Boil  gently,  in  a  test-tube,  2  grams  butter  with  5  c.c.  of 
cold-saturated  solution  of  borax,  and  set  aside  to  cool  and  sub- 
side. Butter  not  sophisticated  leaves  the  borax  solution  nearly  or 
quite  colorless  (with  white  turbidity) ;  artificially  colored  butter 
leaves  the  borax  solution  more  or  less  brown. 

64.  THE  PATS  ARE  DETERMINED  in  Milk — by  separation 
with  ether,  from  the  milk  (a),  from  the  residue  (#)  ;  by  opacity 
of  the  milk  (c) ;  approximately  and  for  comparison  by  the 
volume  of  cream  (d). 

a.  To  20  c.c.  of  milk  add  an  equal  volume  of  10  per  cent, 
solution  of  potassa  (to  hold  the  casein  in  solution),  in  a  cylinder, 
and  repeatedly  extract  with  ether.  Dry  the  ether  residue  at 
110°  C.  [Partner,  see  Phar.  Jour.,  1874,  Sept.  5,  p.  188  ;  also 
Wanklyn's  Milk  Analysis,  New  York,  1874,  p.  24.] 

£.  Evaporate  10  grams  of  milk — with  5  grams  (^resh  dried) 
charcoal  powder  or  15  grams  (just  ignited)  ferric  oxide  or  baric 
sulphate — at  100°  C.,  till  the  weight  is  constant  (total  solids). 
Extract  the  residue,  while  dry  (it  being  very  hygroscopic),  with 
ether,  and  dry  the  ether  residue  at  110°  C. 

c.  Use  of  Vogel's  Lactoscope.  A  test-glass  made  of  two 
semi-circular  glass  plates,  set  parallel  and  exactly  0.5  centimetre 
apart,  to  hold  a  liquid  between.  In  a  mixing  glass,  to  100  c.c. 
of  water,  add  milk  from  a  pipette,  drop  by  drop,  until  the  diluted 
milk,  when  examined  in  the  test-glass,  cuts  off  the  light  of  a 
candle  placed  at  10  to  20  inches  distance  from  the  glass  (the 
examination  being  made  in  a  dark  room).  Dividing  23.2  by  the 
number  of  c.c.  of  milk  required  (to  obstruct  the  light),  then 


MILK. —  GLYCERIN.  85 

adding  to  the  quotient  0.23,  the  sum  is  the  per  cent,  of  fats  in 
the  milk. 

d.  The  milk  is  set  in  a  (wide)  graduated  cylinder  until  the 
cream  has  fully  separated,  when  its  volume  can  be  read  off. 
(The  volume  per  cent,  of  cream  in  cow's  milk  varies  from 
5  to  14.) 

For  Quantitative  Analysis  of  Milk,  see,  farther,  167  and  168. 

65.  FIXED  OILS  ARE  SEPARATED  from  Volatile  Oils  by 
extraction  of  the  latter  with  alcohol  (not  applicable  in  case  of 
castor  oil,  which  is  soluble  in  all  proportions  of  absolute  alcohol 
or  in  4  or  5  parts  of  90  per  cent,  alcohol). — They  are  also 
removed  from  volatile  oils  by  saponification  with  alkalies  and 
water. — They  are  separated  from  substances  soluble  in  water 
by  action  of  that  solvent ;  from  various  solids  by  digestion  with 
ether,  bisulphide  of  carbon,  benzole  or  petroleum  naphtha ;  from 
emulsions  by  spontaneous  separation  in  cream  and  melting  of 
the  latter, .  or  by  ether  or  benzole,  with  addition  of  alkali  if 
necessary  to  prevent  coagulation  of  the  emulsifying  substance. 

Fixed  oils  are  in  many  cases  separated  from  each  other  by 
fractional  fusion,  according  to  differences  of  melting  point  as 
stated  in  the  list,  this  means  of  separation  being  subject  to  the 
same  limitations  mentioned  as  pertaining  to  Fat  Acids  (56). — 
Drying  oils  are  separated  from  non-drying  by  transformation  of 
the  latter  into  elaidin,  as  already  directed. 

66.  GLYCERIN.  C3H5(HO)3.  Characterized  by  its  phy- 
sical properties  (a)  ;  by  the  products  of  its  decomposition  when 
heated  (£)  ;  by  the  limits  of  its  reducing  power  and  its  inter- 
ference with  precipitation  of  metallic  bases  (c). — Separated  from 
solids  by  its  liquidity  at  low  temperatures  •  from  volatile  bodies 
by  their  distillation;  from  sugar,  gum,  or  gelatin  by  certain 
mixed  solvents  (a).  Its  proportion  in  mixture  with  water  is 
determined  from  specific  gravity,  by  use  of  a  table. 

a.  A  colorless,  syrupy  liquid,  of  specific  gravity  1.267  at 
15°  C.,  not  congealed  at  18°  C.  (0°  F.),  mostly  separating  as  a 


86  NEUTRAL  SUBSTANCES,  LIQUID    OR  FUSIBLE. 

liquid  during  the  freezing  of  its  water  mixtures ;  distilling  very 
slowly  with  steam  at  100°  C.,  slowly  giving  off  vapor  with  partial 
decomposition  at  120°  C.  (248°  F.),  boiling  with  decomposition 
of  the  most  part  at  290°  C.  (554°  F.)  Odorless,  and  of  a  pure, 
sweet  taste,  and  neutral  reaction.  Soluble  in  all  proportions  of 
water  and  of  alcohol ;  only  very  slightly  soluble  in  ether,  excess 
of  which  separates  alcohol  from  it ;  not  soluble  in  chloroform ; 
soluble  in  a  mixture  of  2  volumes  of  absolute  alcohol  and  1 
volume  of  ether  (separation  from  Sugar,  Gum,  Gelatin,  etc.)  ; 
soluble  in  a  mixture  of  equal  weights  of  chloroform  and  alcohol 
(separation  from  Sugar,  Dextrin,  Gum,  Extractives — the  mixture 
not  acid)  ;  not  soluble  in  benzole,  bisulphide  of  carbon,  petro- 
leum naphtha,  or  fixed  oils.  It  dissolves  nearly  all  organic  sub- 
stances soluble  in  water  and  many  of  those  soluble  in  alcohol, 
most  salts  of  alkaloids,  and  all  deliquescent  salts  of  metals.  It 
dissolves  baryta,  strontia,  and  lime,  with  combination,  and 
potassa  and  soda  with  gradual  decomposition.  It  holds  salts  of 
iron  and  copper  in  solution  not  precipitated  by  alkalies.  It  dis- 
solves one-fifth  per  cent.,  each,  of  sulphur  and  phosphorus,  20  per 
cent,  of  arsenious  acid,  10  per  cent,  of  benzoic  acid,  15  per  cent, 
of  tannic  acid  (as  a  waxy  solid  melting  at  the  temperature  of  the 
body),  and  dissolves  and  preserves  hydrosulphuric  acid.  It 
strongly  absorbs  water  from  the  air.  It  dissolves  iodine  freely 
without  decomposition,  bromine  sparingly  with  gradual  decom- 
position, and  is  changed  by  chlorine  and  by  nitric  acid.  It  com- 
bines with  strong  sulphuric  acid,  without  color  or  effervescence, 
as  the  instable  glycerosulphuric  acid. 

b.  At  its  boiling  point,  as  above,  glycerin  evolves  suffocating 
vapors  of  acrolein,  etc.,  which  vapors  may  be  condensed  by  ice 
to  a  liquid,  chiefly  acrolein,  with  some  acrylic  acid,  acetic  acid> 
etc.  Acrolein  is  a  very  acrid  body,  boiling  at  51°  C.  (124°  F.), 
soluble  in  40  parts  of  water.  With  acid  sulphate  of  potassium, 
glycerin  evolves  acrolein  at  lower  temperature.  Decomposed 
and  vaporized  in  an  evaporating  dish  over  a  lamp  or  sand- 
bath,  only  a  slight  carbon  residue  remains,  staining  the  dish 


SOAPS. 


87 


(distinction  from  mixture  of  Sugar,  Gums,  etc.,  which  leave  a 
puffy  carbon  residue) . 

c.  Glycerin  does  not  reduce  hot  alkaline  sulphate  of  copper 
solution  (distinction  from  Sugars,  etc.) ;  does  not  reduce  nitrate 
of  silver,  even  on  addition  of  ammonia,  if  dilute  and  not  heated 
(distinction  from  admixtures  of  Formic  acid  and  certain  empy- 
reumatic  matters),  but  on  boiling  it  does  reduce  ammoniacal 
nitrate  of  silver   solution.     (Acrolein,  Butyric  acid,  etc.,  form 
white  precipitates  with  silver  nitrate,  blackening  on  standing  or 
heating.)     At   a   boiling   heat   glycerin   liberates   iodine   from 
iodic  acid. 

d.  As  concentrated  by  evaporation  in  the  air  from  a  water- 
bath,  glycerin  retains  about  5  per  cent,  of  water.     The  U.  S. 
Pharmacopoeia  requires  spec.  grav.  1.25;  the  German  Pharma- 
copoeia spec.  grav.  1.23  to  1.25. 


GLYCERIN   P.   C. 

SP.    GR. 

FREEZING. 

GLYCERIN   P.   C. 

SP.    GR. 

FREEZING. 

10 

1.034 

1°C. 

60 

1.159 

20 
34 
40 

1.051 
1.075 
1.105 

2.5°  C. 
6°C. 
17.5°  C. 

70 
80 
90 

1.179 
1.120 
1.232 

below 
35°  C. 

50 

1.127 

31.34°  C. 

94 

1.241 

67.  SOAPS.  Alkali  salts  of  Fatty  acids  (and  of  Resin 
acids). — Characterized  by  their  peculiar  touch  and  consistence, 
solid  or  gelatinous;  if  solid,  by  melting  or  softening  when 
warmed,  and  more  readily  if  retaining  more  water ;  by  dissolv- 
ing in  water  to  a  slightly  cloudy  solution,  viscid  if  concentrated, 
and  made  more  turbid  by  dilution,  also  dissolving  in  alcohol 
(the  solution  being  often  turbid  from  fats,  alkaline  carbonates,  or 
other  impurities)  ;  by  their  aqueous  solutions  being  precipitated 
by  salts  of  metals  not  alkalies,  or  by  acetic  or  stronger  acids. 
In  the  last-named  precipitation,  the  fatty  acid  will  separate  as  a 
cream,  and  may  be  examined  as  provided  under  head  of  Fat 
Acids,  and  the  base  in  solution  determined  by  inorganic  analysis. 


88  NEUTRAL  SUBSTANCES,  LIQUID   OR  FUSIBLE. 

Soap  solutions  are  precipitated,  physically,  by  common  salt, 
potassa  soaps  becoming  soda  soaps  by  double  decomposition. 
The  oleate  of  potassa  is  (sparingly)  soluble  in  ether ;  otherwise 
the  alkaline  oleates,  stearates,  and  palmltates  are  slightly  or  not 
at  all  soluble  in  ether. 

Quantitative. — a.  In  determining  the  water  of  soaps  by- 
direct  evaporation,  the  fine  shavings  are  exposed  at  first  to  a 
temperature  of  40°  to  50°  C.,  which  is  after  some  time  increased 
gradually,  so  as  not  to  fuse,  to  100°  C.,  the  latter  continued  until 
there  is  no  longer  a  loss  of  weight.  Stearates  so  treated  still 
retain  about  2  per  cent,  water. — A  more  satisfactory  determina- 
tion of  the  water  is  effected  by  dissolving  1  to  2  grams  soap  in 
the  least  sufficient  quantity  of  strong  alcohol,  adding  a  weighed 
quantity  of  fine  sand,  just  dried,  then  evaporating,  with  tritura- 
tion,  and  drying  at  110°  C. — The  water  is  also  estimated  as 
remainder  after  finding  the  fat  acids,  bases  (combined,  free,  and 
carbonated),  glycerin,  resin,  salts,  color-substances,  and  foreign 
matter. 

Z>.  The  amount  of  absolute  soap  is  determined  from  the  fat 
acids  approximately  (GR^EGER)  as  calcium  precipitate  after  solu- 
tion in  alcohol.  Ten  grams  of  the  soap,  in  fine  shavings,  are 
dissolved  in  90  c.c.  of  90  per  cent,  alcohol,  the  solution  made  up 
by  addition  of  alcohol  to  100  c.c.,  left  to  subside,  and  10  c.c.  of 
the  clear  solution  are  taken  out,  diluted  with  water,  and  precipi- 
tated with  calcic  chloride.  The  precipitate  is  gathered  in  a  tared 
filter,  washed,  dried  at  100°  C.,  and  weighed.  100  parts  of  this 
precipitate  indicate  101.5  parts  of  anhydrous  soda  soap. 

c.  The  fat  acids  also  are  determined  gravimetrically,  by 
weight  as  free  acids,  by  intermixture  with  beeswax  (HAGER),  as 
follows:  10  grams  of  the  soap  are  dissolved  by  warming  in  an 
evaporating  dish  in  about  50  c.c.  water,  and  the  solution  treated 
with  6  c.c.  of  hydrochloric  acid  of  spec.  grav.  1.1x54,  or  9  c.c.  of 
dilute  (1  to  5)  sulphuric  acid,  or  enough  to  cause  an  acid  reaction. 
Ten  grams  of  pure  dry  beeswax  are  added,  and  melted,  and  the 
whole  set  aside  to  cool.  The  solidified  mass  is  now  carefully 


QUANTITATIVE  ANALYSIS   OF  SOAPS.,  89 

removed  from  the  solution,  dried  with  blotting-paper,  and 
weighed;  the  weight  being  diminished  by  10  grams  gives  the 
amount  of  fat  acids  [and  resin].  80  parts  of  fat  acid  indicate 
about  100  parts  of  good  dried  (soda)  soap  (HAGER)  ;  11  parts 
fat  acid  represent  an  average  of  12  parts  of  solid  fat. — According 
to  JEAN  ( Chem.  News,  xxvi.,  206)  the  fat  acids  are  estimated 
from  the  combined  alkali  (i),  12.6  parts  of  which  (soda)  unite 
with  100  parts  anhydrous  fat  acids. 

VOHL  (Jour.  Chem.  Soc.,  1872,  934)  separates  the  fat  acids 
(and  resin)  by  a  limited  quantity  of  petroleum  naphtha.  Ten 
grams  of  soap  are  dissolved  in  warm  water,  then  decomposed  by 
hydrochloric  acid  in  a  cylindrical  vessel,  and  the  solution,  at 
20°  C.,  extracted  with  about  10  grams  of  petroleum  naphtha. 
This  solvent  is  afterward  evaporated  in  a  tared  dish  at  30°  C., 
dried  at  100°  C.,  and  the  residue  weighed  as  fat  acids.  As  to 
Resins  in  this  process,  see  g. 

d.  The  fat  acids  may  be  approximately  determined  by  the 
volume  of  their  supernatant  layer,  after  acidulation,  in  a  gradu- 
ated cylinder  (BUCHNER).     1  c.c.  equals  0.93  gram.     The  weight 
of  fat  acid  plus  ^  equals  the  weight  of  fat ;  and  1 00  parts  of  fat 
correspond  to  155  parts  average  hard. soap. 

e.  PONS  recommends  a  volumetric  determination  of  fat  acid 
by  solution  of  calcium  chloride;  on  which  is  based  a  valuation 
of  the  soap,  taking   average  Marseilles  soap — 64  per  cent,  fat 
acids,  6  per  cent,  soda,  and  30  per  cent,  water — as  a  standard  or 
unit  of  value.     One  gram  of  this  standard  soap  will  precipitate 
0.1074  gram  calcium  chloride  (or  0.2532  gram  barium  nitrate)  ; 
or   10.  of  soap,   1.074  of  calcium   chloride,  the  latter  quantity 
being  dissolved   to  make   1,000  c.c.  [1.074  of  calcium  chloride 
may  be  obtained  by  dissolving  0.9675  of  pure  calcium  carbonate, 
the  solution  being  obtained  exactly  neutral.]     Ten  grams  of  the 
soap  (carefully  averaged)   are  dissolved  in   100   c.c.  of  85  per 
cent,  alcohol — insoluble  material  being  removed  by  decantation 
or  nitration,  and  washing — and  distilled  water  is  added  to  make 
the  liquid  measure   1,000  c.c.     In  a  stoppered  flask  of  60  to  80 


90  NEUTRAL   SUBSTANCES,   LIQUID    OR   FUSIBLE. 

c.c.  contents,  place  10  c.c.  of  the  standard  calcium  solution,  and 
add,  from  a  burette  measuring  tenths  c.c.,  the  prepared  soap 
solution,  shaking  after  each  addition  until  a  foam  remains  on  the 
surface  (as  in  the  soap  test  of  hard  Caters).  The  number  c.c. 
used  contains  as  much  soap  as  10  c.c.  of  corresponding  solution 
of  standard  soap  would  contain.  Hence  divide  10  by  the  number 
c.c.  used,  and  the  quotient  expresses  the  value  of  the  soap  tested, 
as  compared  with  the  standard. 

For  the  separation  of  the  fat  acids  from  each  other,  a  work 
of  difficulty,  see  under  Fat  Acids  (55-57). 

f.  TTncombined  fat  can  be  extracted  from   soap  (previously 
dissolved  as  far  as  possible  in  water)  by  petroleum  naphtha  at 
the    temperature    of   20°    C.     (Compare,    under    Butter,    63, 
d  and  e.) 

g.  Resin  can  be  extracted  from  dried  and  pulverized  soap 
by  means  of  benzole,  which  dissolves  only  traces  of  the  soap. — 
Or,  the   solution  of  fat   acids   in  a  little  petroleum  naphtha  (a 
quantity    equal    to    that    of  the    soap) — as   obtained   by  Vohl's 
process,  given  in  c — contains  the  resin,  which  is  now  precipitated 
on  diluting  largely  with  petroleum    naphtha.     The   precipitate 
subsides. — Also,  when  the  fat  acid  (and  resin)  are  treated  writh  a 
mixture  of  water  and  a  nearly  equal  volume  of  alcohol,  the  resin 
is  dissolved  out. 

h.  Soap  may  be  precipitated  from  cold  water  solution  by 
saturated  solution  of  common  salt  (free  from  earthy  bases),  and 
washed  on  a  filter  with  the  same  salt  solution,  with  but  little 
loss,  the  uncombined  alkali  (and  alkaline  carbonate)  and  the 
glycerine  being  contained  in  the  filtrate  and  washings.  The  total 
of  alkali  in  this  filtrate  may  now  be  determined  by  volumetric 
solution  of  acid,  showing  the  uncombined  alkali  of  the  soap,  in- 
cluding alkaline  carbonate. — If  the  soap  is  dissolved  in  alcohol, 
alkaline  carbonates  remain  undissolved  and  may  be  determined 
by  adding  volumetric  solution  of  acid  to  the  residue. — Free 
alkali  may  be  precipitated  from  alcoholic  solution  of  soap  by 
passing  through  a  stream  of  carbonic  acid  gas. — A  qualitative 


QUANTITATIVE  ANALYSIS   OF  SOAPS.  91 

test  for  free  alkali  or  alkaline  carbonate  is  made  by  adding 
mercuric  chloride  to  the  soap  solution;  a  red-brown  to  red- 
yellow  precipitate  indicates  free  alkali — the  fat  acid  salts  forming 
only  white  precipitates. 

i.  Then,  for  volumetric  determination  of  the  combined 
alkali  of  the  soap,  the  soap  precipitate  is  rinsed  (with  dilute 
solution  of  common  salt)  from  the  filter  into  a  beaker,  and 
decomposed  by  a  five-times  stronger  than  normal  standard  solu- 
tion of  (hydrochloric)  acid,  added  to  beginning  of  acid  reaction. 
After  which  the  fat  acid  may  be  separated  as  a  cake  and  weighed, 
according  to  c — a  weighed  quantity  of  beeswax  or  paraffin  being 
added,  if  necessary  to  secure  solidification. 

/  Determination  of  glycerin.  Take  10  grams  of  soap, 
dissolve  in  alcohol,  add  alcoholic  solution  of  sulphuric  acid  until 
precipitation  ceases,  and  filter.  Add  baric  carbonate  and  filter 
again.  Evaporate  until  all  the  alcohol  is  expelled,  and  weigh 
the  sweet  residue  as  glycerin  (SENIER).  Or,  treat  the  filtrate 
from  acid  precipitation  of  the  fat  acids  with  basic  subacetate  of 
lead,  filter,  remove  the  excess  of  lead  by  hydrosulphuric  acid 
and  filtration,  neutralize  with  hydrochloric  acid  and  extract  with 
a  mixture  of  alcohol  2  vols.  and  ether  1  vol.  Evaporate  this 
solvent  and  weigh  as  glycerin  (VOHL). 

k.  A  plan  for  determination  of  the  constituents  of  soap, 
viz. :  (1)  Carbonates  and  other  salts,  color  substances  and  foreign 
matters;  (2)  Free  Alkali;  (3)  Combined  Alkali;  (4)  Fatty 
acids  with  resin ;  (5)  Fatty  acids  without  resin ;  (6)  Glycerin ; 
(7)  Water.* 

For  (1):  Digest  ten  grams  soap  with  alcohol  (five  or  six 
ounces)  on  water-bath,  filter  and  wash  with  hot  alcohol  in  a  hot 
funnel.  Dry  the  residue  at  100°  C.  and  weigh.  Analyze  this 
residue  by  solution  with  water,  by  alkalimetry,  etc. 

For  (2)  :  Through  the  filtrate  of  (1)  pass  a  stream  of  car- 
bonic acid  gas  ;  if  a  precipitate  forms,  continue  until  its  forma- 


:  "  A  Process,"  etc.,  Am.  Jour.  Phar.,  1874, 


92  FUSIBLE    NEUTRAL    SUBSTANCES. 

tion  ceases  ;  filter  and  wash  and  determine  the  alkali  in  the  preci- 
pitate by  a  volumetric  solution  of  (oxalic)  acid.  (See  A.) 

For  (3) :  The  filtrate  from  (2) — or  if  there  was  no  precipitate 
in  (2),  the  filtrate  from  (1) — after  the  addition  of  about  an  ounce 
of  water,  is  evaporated  on  the  water-bath,  to  expel  all  the  alcohol, 
and  the  (combined)  alkali  therein  determined  (as  Soda  or  Potassa) 
by  adding  a  normal  solution  of  oxalic  acid  to  acid  reaction. 
(Compare  i.) 

For  (4) :  To  the  mixture  left  in  (3)  add  a  little  sulphuric 
acid  ;  then  add  ten  grams  of  previously  melted  beeswax,  heat  on 
a  water-bath  to  fuse  the  wax,  cool,  weigh  the  cake,  and  subtract 
the  weight  of  the  wax.  (Compare  c.) 

For  (5)  :  Dissolve  40  grams  of  soap  in  water,  decompose  by 
dilute  sulphuric  acid,  cool  at  temperature  below  14°  C.,  separate 
and  weigh  the  fatty  acids ;  then  digest  them  for  some  time  with 
a  mixture  of  water  with  nearly  as  much  alcohol,  until  the  subsi- 
dent  liquid  (when  the  mixture  has  cooled  and  the  fatty  acids 
again  solidified)  ceases  to  be  milky.  Weigh  the  fatty  stratum 
again  ;  subtract  the  previous  weight,  and  divide  by  four — for  the 
resin  in  10  grams  soap.  (Compare  g.) 

For  (6)  :  Proceed  according  to  the  first  method  under  j. 

For  (7)  :  Estimate  by  difference  ;  or  by  evaporation  of  another 
portion  with  alcohol  and  sand,  as  directed  in  a. 

68.  BESINS.  Compounds  of  C,  H,  and  O.  Vitreous  and 
mostly  brittle  solids  (when  unmixed),  softening  and  melting 
when  gently  heated,  but  not  vaporizable  (distinction  from  cam- 
phors) ;  mostly  heavier  than  water.  The  class  includes  some 
substances  of  pungent  taste,  some  of  poisonous  effect,  and  some 
of  intense  color.  Mostly  insoluble  or  but  slightly  soluble  in 
water :  mostly  soluble  in  absolute  alcohol ;  by  far  the  greater 
number  soluble  in  ether  and  in  benzole  (means  of  separation  from 
gums).  Many  resins  are  soluble  in  aqueous  alkalies,  by  combi- 
nation as  resin-soaps ;  and  in  alcoholic  solution  show  the  acid 
reaction. 


XESINS.  93 

The  resins  of  commerce  include,  first,  vegetable  exudates,  of 
which  the  Resins  proper  mostly  contain  some  extractive  matters; 
the  Gum-resins  being  mixtures  with  gums ;  the  Oleo-resins,  mix- 
tures with  volatile  oils  (including  the  source  of  common  resin  or 
colophony)  ;  and  the  Balsams,  mixtures  with  volatile  oils  and 
acids  formed  by  oxidation  of  volatile  oils.  Second,  resins 
extracted  from  plants  by  alcohol,  including  some  of  both  the  Me- 
dicinal resins  and  the  Color  resins.  And,  third,  resins  obtained 
from  liquid  plant  juices  which  are  dried  as  a  part  of  the  manu- 
facture ;  these  including  two  bodies  insoluble  in  alcohol,  Caout- 
chouc and  Indigo. 

69.  The  separation  of  resins  from  volatile  oils  is  effected  by 
distillation  with  water;  from  gums,  by  fusion   and   straining 
at  100°  C. ;  and  from  various    bodies  and  from  each  other  by 
action  of  the  solvents  applicable  in  the  case.     See  Recapitulation, 
99.     Solution  with  alcohol  and  precipitation  by  pouring  the  solu- 
tion into  water  is  by  far  the  most  generally  applicable  process ; 
solution  with  aqueous  alkali  and  precipitation  by  acid  may  some- 
times be  employed. 

70.  THE  RESINOUS  MATTER  OF  ALOES  is  fusible  on  the  water- 
bath  ;  insoluble  in  cold  water,  partly  .  soluble  in  boiling  water, 
freely  soluble  in  alcohol,  partly  soluble  in  ether,  scarcely  at  all 
soluble  in   chloroform,  benzole,  naphtha,  bisulphide  of  carbon, 
freely  soluble  in  aqueous  alkalies  and  in  glycerin. — ALOES  yields 
paracumaric  acid,  as  follows  :  The  hot  ammoniacal  water  solution 
is  precipitated  with  acetate  of  lead,  the  filtrate  freed  from  lead 
by  dilute  sulphuric  acid,  and  this   second  filtrate  is  boiled  in 
presence  of  the  (excess  of)  sulphuric  acid — forming  (from  resin) 
paracumaric  acid  in  solution.     The  latter  colors  ferric  chloride 
dark  gold-brown. — The  residue  from  an  ammoniacal  solution  of 
material  containing  aloes,  when  saturated  with  hydrochloric  acid, 
yields  the  odor  of  aloes.     Farther,  see  Aloin. 

71.  AMBER  Resin.     Amber  contains  Succinic  acid,  Volatile 
oil,  and  resin  (two  resins).     Amber  is  a  hard  and  brittle,  more 
or  less  transparent  solid,  of  spec.  grav.    1.065;  tasteless,  aro- 


94  FUSIBLE  SUBSTANCES. 

matic  when  rubbed  or  warmed,  of  various  colors,  chiefly  yellow 
or  orange. — Subjected  to  gradually  increasing  heat,  it  softens ; 
at  110°  to  260°  C.,  evolves  a  volatile  oil  colored  blue  by 
hydrochloric  acid  ;  at  about  235°  C.,  evolves  succinic  anhydride ; 
at  287°,  it  fuses;  at  higher  temperatures,  yields  first  a  colorless 
oil,  then  a  yellowish  wax. — Amber  resin  is  insoluble  in  \vater, 
alcohol  (except  -^  which  is  soft  resin),  ether,  benzole,  bisulphide 
of  carbon,  petroleum  naphtha,  volatile  and  fixed  oils,  but  soluble 
in  fixed  alkalies  (except  a  slight  residue)  and  in  concentrated 
sulphuric  acid  (with  a  red  color). — Fuming  nitric  acid  changes 
it  to  a  nitrogenous  resin  of  musk-like  odor  and  gelatinous  con- 
sistence— "  artificial  musk." 

72.  AMMONIAC  Resin.     Ammoniac  contains  72  per  cent,  resin 
and  22  per  cent,  gums,  and  a  little  volatile  oil.     Ammoniac  is  a 
solid,  soft  when  warmed,  brittle  when  cold,  of  specific  gravity 
1.207,  whitish  to  yellow-brown  and  dirty  gray,  of  a  sweetish- 
bitter  and  acrid  taste  and  strong  peculiar  odor.     Ammoniac  is 
partly  soluble  in  water,  alcohol,  ether,  acetic  acid,  and  aqueous 
alkalies.     Ammoniac  Resin  is  wholly  soluble  in  alcohol,  in  fixed 
and  volatile  oils,  in  sulphuric  acid,  acetic  acid,  and  aqueous  alka- 
lies, and  partly  soluble  in  ether. 

73.  ASSAFETIDA   Resin.     Assafetida   contains   over   60    per 
cent  of  resin,  about  30  per  cent,  of  gums,  and  about  4  per  cent. 
of  volatile  oil  (whereon  its  odor  depends).     Assafetida  is  a  solid, 
soft  when  warm,  and  brittle  when  cold,  of  spec.  grav.  1.327, 
having  an  intense  fetid  and  alliaceous  odor  and  a  bitter,  acrid, 
and  persistent  taste.     Its  color  is  variegated  and  altered,  being 
on   fresh   surfaces    whitish  to  yellowish,   becoming   reddish   to 
yellow-brown  on  exposure. — The  volatile  oil  is  separated  by  dis- 
tillation with  water,  contains   sulphur,  and  boils  at  140°  C. — 
Assafetida  resin  is  readily  soluble  in  alcohol,  not  wholly  insolu- 
ble in  water,  nearly  all   soluble    in    ether,    mostly    soluble  in 
alkalies. 

74.  BENZOIN    Resins.     Benzoin   or  "  benzoin-gum "   consists 
of  about  three-fourths  part  resin's,  10  to  15  per  cent,  of  Benzoic 


RESINS.          ,  95 

acid,  with  a  little  gum  and  a  very  little  volatile  oil.  Benzoin  is  a 
brittle  solid,  of  spec.  grav.  above  1.062,  melting  and  evolving 
benzoic  acid  when  heated ;  of  variegated  colors,  fragrant  bal- 
samic odor,  and  little  taste,  with  slight  acrid  after-taste  when 
chewed.  Benzoin  resins  (three  have  been  identified)  are  all 
soluble  in  alcohol,  in  concentrated  sulphuric  acid  (from  which 
water  precipitates  them  violet),  and  in  strong  potassa  solution, 
but  insoluble  in  water.  Resin-a  is  insoluble  in  aqueous  carbon- 
ate of  sodium,  or  in  ammonia,  but  soluble  in  ether.  Resin-J  has 
the  solubilities  above  given  for  a,  except  that  it  is  insoluble  in 
ether.  Resin-c  is  sparingly  soluble  in  ether  and  in  volatile  oils, 
and  soluble  in  aqueous  carbonate  of  sodium.  The  ether  solution 
of  c  deposits  a  sediment  which  has  been  considered  a  fourth 
resin. — Dry  distillation  of  benzoin,  after  removal  of  benzoic 
acid,  gives  a  rose-red  distillate. 

75.  CANAUBA  WAX.     Consists  of  myristic  alcohol,  resin,  and 
other  substance.     It  is  a  solid  of  spec.  grav.  0.999,  harder  than 
beeswax,  melting  at  84°  C.,  and  of  a  greenish-yellow  color.     It 
is  insoluble  in  water;    dissolves  with   difficulty  in  alcohol,  in 
ether,  and  in  bisulphide  of  carbon ;  dissolves  readily  in  oil  of 
turpentine,  but  not  at  all  in  linseed  oil,  and  not  in  aqueous  alka- 
lies.    It  is  not  changed  by  sulphuric  acid,  but  is  stained  deep 
yellow  by  nitric  acid. 

76.  CAOUTCHOUC.     Fusible  at  120°  C.  (248°  F.)  ;  not  vapor- 
izable.     T}ie  larger  part  soluble  in  ether,  benzole,  bisulphide  of 
carbon,  petroleum  naphtha,  or  oil  of  turpentine ;  wholly  soluble 
in  chloroform,  and  in  a  mixture  of  100  parts  bisulphide  of  carbon 
with  6  or  8  parts  of  absolute  alcohol.     Sparingly  soluble  in  hot 
amylic  alcohol.     Not  acted  upon  by  alcohol  or  aqueous  alkalies  ; 
slowly  decomposed  by  concentrated  sulphuric  or  nitric  acid. 

77.  COLOPHONY.     Resin  of  Turpentine.     Common  Resin  or 
Rosin. — A  pale-yellow  to  brownish-yellow,  translucent,  brittle, 
vitreous  solid,   of  spec.   grav.  of  1.07  to  1.08;    softening  at  70° 
C.  and  melting  at  135°  C.     At  a  higher  temperature  it  suffers 
destructive   distillation,    forming  "  essence   of  rosin "   and    then 


95  FUSIBLE    SUBSTANCES. 

"rosin  oil." — Insoluble  in  water;  soluble  in  alcohol,  ether, 
chloroform,  benzole,  petroleum  naphtha  (with  much  difficulty), 
volatile  and  fixed  oils,  methylic  alcohol,  aqueous  alkalies  (fixed 
and  volatile),  anilin,  and  hot  aqueous  carbonate  of  sodium.  The 
three  constituents — pinic,  sylvic,  and  colopholic  (or  pimaric) 
acids — vary  in  solubility  in  certain  solvents  ;  cold  dilute  alcohol 
dissolving  only  pinic  acid. 

78.  COPAIBA  RESINS.     Balsam  of  Copaiba  consists  of  several 
resins  and  a  volatile  oil  (a  terpene) .     The  most  abundant  of  these 
resins,  COPAIVIC  ACID  (the  proportion  of  which  is  very  variable), 
is  a  brittle  solid,  crystallizable  in  colorless  rhombs ;  soluble  in 
strong  alcohol,  ether,  benzole,  petroleum  naphtha,  volatile  and 
fixed  oils,   and   aqueous  alkalies.     Its  alcohol  solution  reddens 
litmus.    Alcohol  solutions  of  the  alkaline  copaivates,  with  alcohol 
solutions  of  salts  of  non-alkaline  metals,  on  adding  water,  preci- 
pitate white  metallic  copaivates,  more  or  less  freely  soluble  in 
alcohol.     The  silver  precipitate  is  crystalline,  and  the  lead  preci- 
pitate slightly  so. — The  other  resins  are  soluble  in  alcohol,  ether, 
fixed  and  volatile  oils,  and  aqueous  alkalies. 

79.  COPAL.     Spec.  grav.  1.045  to  1.139.     Brittle,  softening 
at  50°  C.,  more  or  less  translucent,  colorless  to  yellowish-brown. 
Consists  of  several  resins.     As  a  whole,  it  is  imperfectly  soluble 
in  alcohol ;  slightly  and  slowly  soluble  in  ether,  bisulphide  of 
carbon,  ammonia ;  slowly  soluble  in  oil  of  turpentine ;  readily 
soluble  in  oil  of  cajeput,  or  oil  of  rosemary,  or  "  oil  of  caout- 
chouc."    It  is  soluble  in  cold  concentrated  sulphuric  and  nitric 
acids,    decomposing    when    these    solutions   are   heated.      Not 
soluble  in  alkalies ;  but  combines  with  alkalies  in  boiling  solu- 
tion to  form  a  soap  soluble  in  water  not  containing  free  alkali. 

80.  DAMMARA   Resin.     Australian.     Dammaric   acid   with 
Dammaran — that  is,  an  acid  and  a  neutral  resin. — Both  resins 
are  soluble  in  absolute   alcohol,  ether,  turpentine  oil,  benzole, 
petroleum  naphtha,  and  solutions  of  fixed  alkalies.     The  acid 
resin  is  soluble,  the  neutral  resin  insoluble  in  aqueous  alcohol. — 
East  Indian  dammara  (ordinary  dammara).     Spec.  grav.  1.04 


RESINS.  97 

to  1.09,  brittle,  melting  when  heated.  Partially  soluble  in 
absolute  alcohol,  about  T3^  soluble  in  ether,  fully  soluble  in  fixed 
and  volatile  oils,  benzole,  and  bisulphide  of  carbon,  and  in  con- 
centrated sulphuric  acid  with  a  red  color.  It  is  not  soluble  in 
aqueous  alkalies. 

81.  DRAGON'S  BLOOD.     A  brittle,  dark-brown,  opaque,  odor- 
less, and  tasteless  solid ;    soluble   (with  red  color)  in  alcohol, 
ether,   fixed  and  volatile  oils,  and  mostly  soluble  in  alkalies. 
The    alcoholic  solution   forms   red   or   violet  precipitates  with 
metallic  salts. 

82.  GAMBOGE  Eesin.     Gamboge  is  over  three-fourths  resin ; 
the  rest  mostly  gums,  with  a  little  starch.     Gamboge  is  a  brittle, 
pulverulent  solid,  of  spec.  grav.  1.22,  burning  when  heated;  red- 
dish-yeljow  in  mass,  bright  yellow  in  powder ;  nearly  odorless  at 
ordinary  temperatures,  but  giving  a  peculiar  odor  when  heated  ; 
a  slight  first-taste  but  a  sweetish-acrid   and  dry  after-taste  when 
chewed,  causing  a  flow  of  yellow-colored  saliva. — Gamboge  is 
easily  emulsified  with  water,  which  dissolves  gum  from  it,  the 
resin  being  slowly  deposited ;  is  readily  soluble  in  alcohol  (with 
a  little  starchy  residue),  is  soluble  in  aqueous  alkalies,  and  yields 
its  resin  (only)  to  the  solvent  powers  of  ether,  chloroform,  bisul- 
phide of  carbon,  and  benzole  (slowly) .     Boiling  solution  of  sodic 
carbonate  dissolves  gamboge  gelatinous.     Gamboge  is  wholly 
dissolved  by  the  successive  action  of  ether  and  water  (separation 
from   commercial    impurities) . —  Gamboge    Resin   ("  gambogic 
acid  " — usually  extracted  from  gamboge  by  ether)   is  soluble  in 
cold,  concentrated,  sulphuric  acid,  with  a  red  color,  and  precipi- 
tated unchanged  by  adding  water  to  this  solution   (a  characteris- 
tic reaction).     Boiled  with  nitric  acid  of  10  to  15  per  cent,  anhy- 
dride, the  mixture  then  dissolved  in  alcohol  and  then  treated  with 
water,  a  yellow  precipitate  is  obtained  (distinction  from  Saffron 
or  Turmeric). — The  aqueous  alkaline  gambogates  are  precipitated 
red  by  common  salt,  and  give  red  precipitates  with  baric  salts, 
yellow  precipitates  with  zincic  and  plumbic  salts,  brown  precipi- 
tates with  cupric  salts,  and  brownish-yellow  with  argentic  salts 


98  FUSIBLE    SUBSTANCES. 

— most  of  these  precipitates  being  somewhat  soluble  in  water  and 
in  alcohol. 

For  the  separation  of  gamboge  resin  from  associated  medi- 
cinal resins  (HAGER)  the  material  is  triturated  with  98  per  cent, 
alcohol  (and  pulverized  heavy  spar)  at  a  gentle  heat,  and  the 
extract  so  obtained  is  dried  and  digested  with  chloroform.  Aloes 
resin,  Convolvulin,  and  Colocynth  resin  are  left  behind  (with 
a  part  of  Agaric)  ;  while  the  gamboge  resin  is  dissolved,  with 
Jalapin,  Guaiac  resin,  Myrrh,  Tolu  resin,  Senna  resin  (and 
a  part  of  Agaric).  The  residue  from  this  chloroform  solution 
is  now  digested  with  boiling  solution  of  sodic  carbonate ;  when, 
of  those  named  above  as  in  the  chloroform  solution,  only  the 
gamboge  resin  will  dissolve  (with  traces  of  senna  and  agaric). 
Acids  separate  the  gamboge  resin  from  its  soda  solution. 

83.  GUAIACUM.     A  brittle,  pulverizable  solid,  of  spec.  grav. 
about  1 .2,  melting  at  a  moderate  heat ;  of  a  faintly  fragrant  odor 
and  persistent  acrid  after-taste.     Its   color  is  yellowish-green  to 
reddish-brown ;  the  former  color  induced  by  exposure  to  the  air. 
Water  dissolves  a  one-tenth  of  guaiac  resin,  strong  alcohol  about 
nine- tenths,  alcohol  of  83  per  cent,  slowly  dissolves  it  all.    Ether 
and  oil  of  turpentine  dissolve  about  as  much  as  alcohol ;  benzole 
does  not  dissolve  it.     It  nearly  all  dissolves  in  aqueous  alkalies. 
Sulphuric  acid  dissolves  it  with  a  fine  red  color  (and  formation 
of  glucose  and  guaiaretin)  ;  the    solution  is  precipitated  violet 
with  water,  or  violet- blue  to  blue-green  by  alcohol. — Guaiac  resin 
is  easy  to  suffer  oxidation,  whereby  bright  colors  are  produced. 
The  powder  and  the  alcoholic  solution  turn  green  by  exposure  to 
the  air,  or  blue  by  exposure  to  ozone.     The  alcohol  solution  is 
also  turned  green  by  nitric  acid,  and  blue  by  nitrous  acid,  chlo- 
rine, ferric  chloride,  or  by  ethereal  solution  of  binoxide  of  hydro- 
gen in  presence  of  blood-stains.     Hyposulphite  of  sodium  changes 
the  blue  color  to  violet  and  then  bleaches  it ;  sulphurous  acid 
bleaches  it  slowly — or  promptly  if  zinc  has  been  placed  in  the  acid. 

84.  HEMP    RESIN.     Cannabin.     Resin  of  Indian  hemp. — A 
light-brown,  lustrous  solid  or  soft  solid,  melting  at  68°  C.,  and 


RESINS.  99 

of  a  fragrant  odor  and  bitterish,  acrid  taste.  Insoluble  in  water, 
scarcely  soluble  in  cold  alcohol  of  80  per  cent.,  soluble  in  hot, 
strong  alcohol,  in  ether,  spirit  of  nitrous  ether,  chloroform,  bisul- 
phide of  carbon,  cold  volatile  oils,  and  warm  fixed  oils.  Insolu 
ble  in  aqueous  alkalies ;  having  a  neutral  reaction. 

85.  INDIGO    BLUE.      C8H6NO.       Inodorous,    tasteless,    an4 
neutral.     Sublimes  from  the  solid  state,  at  about  288°  C.,  witk 
out  decomposition  if  in  a  current  of  air  or  in  vacuum,  forming 
purple-red    vapors    in    open   vessels,    and    condensing    in    right 
rhombic  prisms. — It  is  insoluble  in  water,  cold  alcohol,  ether, 
fixed  and  volatile  oils  when  cold ;  hot  alcohol  and  hot  oil  of  tur- 
pentine and  hot  fixed  oils  dissolving  it  very  sparingly.     Insoluble 
in  aqueous  alkalies.     Soluble  in  creosote  and  in  hot  phenic  acid ; 
soluble  in  concentrated  sulphuric  acid  (as  sulphindigotic  acid). — 
Indigo  blue  is  separated  from  fixed  substances  by ,  sublimation 
from  platinum  foil  (good  indigo  having  7  to  10  per  cent,  of  ash) ; 
and  by  the  use  of  solvents  which  leave  it  in  residue.     It  is  valued1, 
in   numerous    processes,   by   the   quantity   of  chlorine   or  other 
bleaching  agent  necessary  to  decolorize  it. 

86.  JALAP  RESINS.     Eesin  of  Jalap,  of  the  pharmacopoeias. — 
A  brownish,  brittle,  opaque,  fusible  mass,  or  yellowish-gray  to 
yellowish- white  powder ;  of  a  repulsive  odor,  slight  at  ordinary 
temperatures,  but  much  increased  on  heating,  and  a  pungent, 
acrid  taste. — It  is  soluble  in  alcohol  (with  neutral  reaction),  in 
aqueous  fixed  alkalies  and  alkaline  carbonates,  and  in  acetic  acid ; 
insoluble  in  volatile  and  fixed  oils. — Resin  of  jalap  consists  of 
two  distinct  resins,  Jalapin  and  Convolvulin ;  that  of  pharmaco- 
pceial  or  Tuberose  jalap  being  about  one-ninth  jalapin  and  eight- 
ninths  convolvulin  ;  that  of  Fusiform  jalap,  mostly  jalapin. 

87.  JALAPIN    (or   Scammonin)    is    a    soft   amorphous    solid, 
brittle  at  100°  C.,  melting  at  150°  C.,  white  in  powder,  tasteless, 
inodorous,  and  nearly  neutral   in  reaction.     It  is  very  slightly 
soluble  in  water ;  freely  soluble  in  ether,  chloroform,  methylic 
alcohol,  benzole,  petroleum  naphtha,  and  oil  of  turpentine.     Cold 
concentrated  sulphuric  acid  dissolves  jalapin;  the  solution  be- 


100  FUSIBLE  SUBSTANCES. 

coming  purple  in  five  or  ten  minutes,  then  brown,  and  lastly 
black. — It  dissolves  in  aqueous  alkalies  or  their  carbonates,  and, 
on  acidulating  these  solutions,  Jalapic  (Scammonic)  acid  is 
liberated — as  a  body  soluble  in  water  and  having  a  strongly  acid 
reaction.  The  salts  of  jalapic  acid  are  nearly  all  soluble  in 
water,  but  subacetate  of  lead  precipitates  it. — On  heating  Jalapin 
(or  Jalapic  acid)  with  dilute  mineral  acids,  glucosic  fermentation 
occurs,  with  formation  of  jalapinol  and  glucose.  Jalapinol  is  in- 
soluble in  cold,  sparingly  soluble  in  hot  water,  soluble  in  alcohol 
and  in  ether;  soluble  in  aqueous  alkalies  with  combination  as 
jalapinolic  acid.  Jalapinolic  acid,  liberated  from  its  alkali  salts 
by  acidifying,  is  insoluble  in  water,  but  soluble  in  alcohol  and  in 
ether.  Its  lead  and  barium  salts  are  nearly  insoluble  in  water. — 
Jalapin  and  jalapic  acid  are  amorphous  ;  jalapinol  crystallizes  in 
white  cauliflower-like  masses,  melting  at  62°  C. ;  jalapinolic  acid 
crystallizes  in  tufts  of  needles  (four-sided  prisms),  melting  at 
62°  C. 

88.  CONVOLVULIN  (the  larger  portion  of  Tuberose  jalap  and 
a  very  small  proportion  of  Fusiform  jalap)  is  a  brittle,  vitreous 
solid,  melting  below  100°  C.  when  moist,  or  at  150°  C.  when  dry, 
colorless  and  transparent  in  mass,  or  white  in  powder,  inodorous 
and  tasteless,  and  of  a  slight  acid  reaction. — Nearly  insoluble  in 
water ;  soluble  in  alcohol,  acetic  acid,  and  aqueous  alkalies  and 
alkaline  carbonates  (as  convolvulinic  acid) ;  not  soluble  in  ether 
(separation  from  Jalapin). — It  dissolves  slowly  in  cold  concen 
trated  sulphuric  acid,  with  a  fine  carmine-red  color,  afterward 
changing  to  brown ;  this  change  being  a  glucosic  fermentation, 
with  formation  of  convolvulinol  and  glucose.  But  dilute  sul- 
phuric acid  has  no  effect. — Convolvulic  acid  is  formed  in  acidify- 
ing the  alkaline  solutions  of  convolvulin ;  it  is  a  white  solid, 
fusing  above  100°  C.,  having  a  strong  acid  reaction,  and  freely 
soluble  in  water  and  alcohol,  insoluble  in  ether.  Its  metallic 
salts  are  soluble,  except  that  formed  with  basic  acetate  of  lead. 

39.    LAC    Resin.     Stick    Lac   consists   of    about    two-thirds 
resin,   one-tenth  coloring  matter,  with  wax,  gluten,  etc.     Seed 


> 
mama.  101 

X0       <5>  ^x^ 

Lac  contains  more  resin  and  less  coloring  and  nitrogenous  matter. 
Shell  Lac  is  about  90  per  cent,  resins,  5  per  cent,  wax,  2.5  per 
cent,  gluten,  and  0.5  per  cent,  coloring.  The  coloring  matter  of 
lac  is  soluble  in  water ;  is  bright  red  with  acids  and  deep  violet 
with  alkalies  ;  is  precipitated  by  alum. 

Shell  Lac  is  insoluble  in  water ;  soluble  in  alcohol ;  mostly 
soluble  in  methylic  alcohol ;  wholly  soluble  in  aqueous  alkalies, 
and  in  water  solution  of  borax,  and  in  hydrochloric  and  acetic 
acids. — Lac  resin  is  separated  from  most  other  resins,  and  from 
many  natural  and  commercial  impurities,  by  dissolving  in  a  solu- 
tion of  J  part  borax  and  20  to  30  parts  water  to  one  part  of  lac. 
The  solution  may  be  diluted  farther.  (Good  shell  lac  leaves  not 
over  1.5  per  cent,  residue ;  poor,  as  much  as  8  per  cent.)  By  10 
per  cent,  ammonia  at  25°  to  30°  C.  lac  is  not  dissolved,  while 
Colophony  dissolves  and  appears,  after  acidulation,  as  a  precipi- 
tate. Cold  ether  (of  0.720  spec,  grav.)  does  not  dissolve  more 
than  5  to  6  per  cent.,  chloroform  not  over  7  J  per  cent,  from  good 
lac,  the  dissolved  part  being  wax  with  a  very  little  resin  (separa- 
tion from  Colophony  and  other  resins). 

90.  MASTIC.     A  translucent  solid,  brittle  and  inodorous  at 
ordinary  temperatures,  but  soft  and   ductile  when  chewed  and 
fragrant  when  heated,  of  a  faintly  terebinthinate  taste.     Alcohol 
dissolves  about  four-fifths,  leaving  Masticin  undissolved.     Ether, 
chloroform,  and  oil  of  turpentine  dissolve  it  wholly.    It  is  largely 
soluble  in  benzole. 

91.  MYRRH  Resin.     Consists  of  resins,  about  -J-  part ;  gums, 
about  -|  part;    with   a   very  little    soluble  extractive.     Myrrh 
forms  an  emulsion  and  partial  solution  with  water,  a  nearly  com- 
plete solution  with  much  aqueous  potassa,  and  yields  its  resin  to 
alcohol,  ether,  and  chloroform. — The  Resin  of  Myrrh  is  readily 
soluble  in   alcohol,  ether,  chloroform ;    slightly  soluble  in  hot 
solution  of  sodic  carbonate ;  about  one-half  part  soluble  in  bisul- 
phide of  carbon.     That  part  extracted  with  bisulphide  of  carbon, 
when  dissolved  in  alcohol  and  warmed  with  25  per  cent,  nitric 
acid,  gives  a  violet  color. 


102  FUSIBLE  SUBSTANCES. 

92.  OLIBANUM   Resin.     Frankincense.     Incense. — Olibanum 
is  about  one-half  part  resin,  one-third  part  gum,  one-twelfth  part 
volatile  oil.     The  gum  is  soluble  in  water ;  the  resin  is  soluble 
in  alcohol. 

93.  Resin  of  PERU  Balsam.     About  £  resins,  f  volatile  oil, 
less  than  -^  cinnamic  acid.     The  Balsam  is  of  thick-syrupy  con- 
sistence; spec.  grav.   1.15  (sinks  in  an  18  per  cent,  solution  of 
common  salt).     Soluble  in  absolute  alcohol  in  all  proportions,  or 
in  6  parts  of  90  per  cent,  alcohol  with  slight  turbidity  ;  perfectly 
soluble  in  all   proportions   of  absolute  ether,    chloroform,    and 
amylic   alcohol.     Bisulphide    of    carbon   dissolves    the   greater 
part;  benzole  and  petroleum  naphtha  dissolve  about  one-half. 
It  mixes  with  about  -J  part  of  castor  oil,  and  with  1  part  copaiba 
balsam.     Sulphuric  acid  converts  the  balsam  into  a  thick  red 
mass.     Aqueous  alkalies  dissolve  out  the  resin.     10.0  of  the  bal- 
sam requires  over  0.7  grams  crystallized  sodic  carbonate  to  neu- 
trallize  its  cinnamic  acid. 

94.  PODOPHILLUM  RESIN.     Consists  of  two  resins.     Insoluble 
in  water ;  wholly  soluble  in  alcohol ;    about  J  part  soluble  in 
ether ;  wholly  soluble  in  aqueous  alkalies,  from  which  solutions 
acids  precipitate  it  (distinction  from  resins  of  Jalap  and  Scam- 
mony).     Insoluble  in  benzole. 

95.  SANDARAC.     A   brittle,   yellow   solid.     Contains    three 
resins.     Sandarac    is    insoluble    in    water;    wholly    soluble   in 
alcohol- — j-  part  dissolving  easily  in  cold  ordinary  alcohol,  a  small 
part  requiring  boiling  alcohol,  and  a  still  smaller  part  a  large 
quantity  of  this  solvent  for  solution.     It  is  easily  soluble  in  ether 
and  in  oil  of  turpentine,  imperfectly   soluble  in  bisulphide  of 
carbon,  benzole,  petroleum  naphtha,  or  linseed  oil.     Nitric  acid 
colors  it  clear  brown. 

96.  SCAMMONY  Resin.     Convolvulin.     See  Jalapin  (87). 

97.  Resinous  part  of  STORAX.     Consists  of  (two)  resins,  and 
Styracin  or  Cinnamate  of  Cinnyl  (C9H9C9H7O2) .     Alcohol  and 
ether  dissolve  the  whole.     In  cold  alcohol,  the  styracin  crystal- 
lizes in  tufts  of  prisms.     Styracin  is  tasteless  and  odorless,  more 


103 

freely  soluble  in  ether  than  in  alcohol.  Treated  with  hot  nitric 
acid,  or  with  chromic  acid,  or  with  sulphuric  acid  and  binoxide 
of  manganese,  it  yields  benzoyl  hydride  (oil  of  bitter  almonds). 

98.  Resins  of  TOLU  Balsam.     The  Balsam  consists  of  80  to 
90  per  cent,  of  resin,  about  12  per  cent,  of  cinnamic  acid,  and 
less  than   1   per  cent,  of  volatile  oil.     It  is  wholly  soluble  in 
alcohol,  chloroform,  volatile  oils,  and  aqueous  alkalies  ;  partly 
soluble  in  ether  ;  insoluble  in  benzole,  petroleum  naphtha,  bisul- 
phide  of  carbon,  and  solution  of  carbonate   of  sodium.     The 
Resins  of  Tolu  balsam  are  soluble  in  cold  concentrated  sulphuric 
acid,  without  change. 

99.  Separation  of  Resins  by  Solvents.     Recapitulation. 
— Water  dissolves  a  part  of  the  resin  of  Assafetida,  a  part  of 
Gamboge,   about  -^  of    Guaiac   resin,   and   slightly   dissolves 
Jalapin. 

a.  Alcohol  fails  to  dissolve  -^  of  Amber,  Canatiba  wax, 
Caoutchouc,  a  part  of  Copal,  -^  of  Guaiacum,  Indigo  blue  (dis- 
solving slightly  with  heat),  and  -J  of  Mastic. 

b.  Aqueous  Alkalies  (potassa  or  soda)  dissolve  Aloes  resin, 
Amber,  Ammoniac,  Assafetida   (mostly),  Benzoin,   Colophony, 
Convolvulin    (with   change),   Dammara    (Australian),   Dragon's 
Blood   (mostly),   Guaiacum,  Jalapin  (with  change),   Lac   resin, 
Myrrh,  and  resins  of  Podophyllum  and  of  Peru  and  Tolu  bal- 
sams.— These  solvents  do  not  dissolve  Canatiba  wax,  Caoutchouc, 
Copal,  Dammara  (East  Indian),  Hemp  resin,  Indigo  blue. 

c.  Ether    dissolves  resin   of  Aloes,   Ammoniac    (in    part), 
Assafetida  resin  (mostly),  Benzoin  (in  part),  Canatiba  wax  (with 
difficulty),  Caoutchouc  (mostly),  Colophony,  Copal  (with  diffi- 
culty), Dammara  (in  part),  Dragon's  Blood,  Gamboge,  Guaiacum 
(in  greater  part),  Hemp  resin  (Cannabin),  Jalapin,  Mastic,  resin 
of  Peru  balsam,  |-  of  Podophyllum   resin,  Sandarac,  Styracin, 
and  resin  of  Tolu   balsam. — Ether   does   not  dissolve  Amber, 
Indigo,  and  j-  of  Podophyllum  resin. 

d.  Chloroform  dissolves  Caoutchouc,  Colophony,  Gamboge, 
Guaiacum,    Hemp    resin  (Cannabin),   Jalapin,    Mastic,   Myrrh, 


104  NEUTRAL   SUBSTANCES,   LIQUID    OR   FUSIBLE. 

resin  of  Peru  balsam,  resin  of  Senna,  resin  of  Tolu  balsam. 
— Chloroform  does  not  dissolve  Agaric  (in  chief  part),  resin  of 
Aloes,  resin  of  Colocynth,  Convolvulin. 

6.  Bisulphide  of  Carbon  dissolves  Canatiba  wax,  Caoutchouc, 
Copal  (slowly),  Dammara,  Gamboge,  Hemp  resin,  J  of  Myrrh, 
resin  of  Peru  balsam,  Sandarac  (in  part). — It  does  not  dissolve 
Amber,  Indigo  blue,  \  of  Myrrh,  resin  of  Tolu  balsam. 

f.  Benzole    dissolves    Caoutchouc,    Colophony,    Dammara, 
Gamboge,  Jalapin,  Mastic   (mostly),  £  of  the  resins  of  Peru 
balsam,  Sandarac  (in  part).     Benzole  does  not  dissolve  Amber, 
Guaiacum,  resin  of  Podophyllum,  resin  of  Tolu  balsam. 

g.  Oil  of  Turpentine  dissolves  Ammoniac,  Benzoin  resin  (in 
part),   Canaiiba  wax,   Caoutchouc,    Colophony,    Copal    (slowly), 
Dammara,   Dragon's  Blood,   Guaiacum   (mostly),   Hemp  resin, 
Jalapin,  Mastic,  Sandarac,   resin  of  Tolu  balsam. — It  does  not 
dissolve  Amber,  Indigo  (without  heating). 

h.  Sulphuric  Acid,  concentrated,  cold,  dissolves  Amber  (with 
red  color),  Ammoniac,  Benzoin  resin,  Convolvulin  (with  red 
color  turning  brown),  Copal,  Dammara  (with  red  color),  Gam- 
boge (with  red  color),  Guaiacum  (with  red  color,  etc.),  Indigo 
blue. — It  does  not  dissolve  Caoutchouc. 

100.  VOLATILE  OILS.     In  composition,  1st,  Hydrocar- 
bons,   or   "  elaeoptenes,"   mostly    of  the    formula    (C10H16)ft-,    a 
large  class; 

2d,  Oxidized  oils  (C,  H,  O),  including  (1)  hydrates  of  hydro- 
carbons, the  "  stearoptenes "  or  camphors,  a  moderate  number 
being  found  alone  and  a  large  number  in  mixtures  with  the  else- 
optenes,  (2)  aldehydes,  (3)  compound  ethers,  generally  in  natural 
mixture  with  elseoptenes,  (4)  of  irregular  composition ; 

3d,  Sulphurized  oils  (C,  H,  O,  S) ,  a  small  class,  products  of 
natural  fermentation,  and  having  odors  resembling  each  other. 

101.  Mostly  liquids,  a  few  oils  and  stearoptene  parts  of  oils 
melting   at   a   little  above   ordinary   temperature ;    the  greater 
number  lighter,  a  few  heavier,  than  water ;  very  slowly  volatile 


VOLATILE   OILS.  105 

at  ordinary  temperatures,  mostly  having  boiling  points  above 
150°  C.,  but  all  distilling,  slowly,  with  steam  at  100°  C.,  and 
leaving  a  transient  oil-spot  on  paper.  They  are  noted  for  strong 
and  persistent  odors  ;  colorless,  or  with  pale  colors,  in  a  few 
instances  tinted  blue  with  coerulein,  transparent  and  possessed  of 
strong  refractive  powers. — The  volatile  oils  are  neutral  in  reac- 
tion •  not  generally  liable  to  decomposition  or  combination 
except  with  oxygen.  By  air  and  light  many  of  them  alter  and 
form  resinous  bodies ;  the  elaeoptenes  forming  stearoptenes,  and 
(by  oxidizing  agents)  aldehydes  forming  acids. 

102.  Volatile  oils  are  very  sparingly  soluble  in  water,  requir- 
ing intimate  mixture  and  generally  from  600  to  1,000  parts  of 
water  for  solution ;  soluble  in  alcohol,  and  in  all  proportions  of 
absolute  alcohol,  ether,  chloroform,  benzole,  petroleum  naphtha, 
bisulphide  of  carbon,  fixed  oils  and  other  volatile  oils.     Alkalies 
do   not  affect  them. — Certain  oils,  after  distillation  with  water, 
retain  traces  of  water  in  solution.     This  occurs  with  oils  of  ber- 
gamot,    cinnamon,   cloves,  juniper,  lavender,   lemon,   rosemary, 
sassafras,  spike,  wintergreen ;  not  with  oils  of  amber,  cedar,  rue, 
turpentine.     The  presence   of  water  is  shown  by  turbidity  on 
mixture  with  several  volumes  of  petroleum  naphtha  (LEUCHS). — 
Volatile  oils  are  scarcely  at  all  soluble  in  aqueous   solutions  of 
chloride,  nitrate  or  sulphate  of  sodium. 

103.  The  volatile  oils  are  characterized  by  their  individual 
odors,  their  physical  properties  (as  stated  above  and  in  105  and 
106),  by  various  special  reactions  (the  most  of  which  are  stated 
in  107  to  114),  by  their  refractive  indices  and   their  absorption 
spectra,  and  by  their  cohesion-figures  when  dropped  upon  a  still 
surface  of  pure  water.* 

104.  Volatile  Oils  are  separated   from   substances  more 
or  less  volatile  by  their  distillation  with  steam ;  from  many  sub- 
stances by  their  slight  solubility  in  water  (farther  lessened  by 


*  TOMLINSON,    MOFFAT  :    Chem.   News,    1869.     CRANE  :    Am.    Jour. 
Phar.,  1874,  Sept.,  and  Phar.  Jour.,  1874,  p.  242,  et.  seq. 


106  NEUTRAL  SUBSTANCES,  LIQUID   OR  FUSIBLE. 

common  salt)  and  ready  solubility  in  alcohol,  ether,  etc. — From 
Fixed  Oils  they  may  be  separated  by  distillation  with  water ; 
by  solution  in  alcohol  (not  from  castor  oil)  ;  or  by  alkaline 
saponification  of  the  fixed  oil. 

From  Alcohol,  they  may  be  separated  (in  greater  part)  by 
addition  of  water ;  (in  part)  by  addition  of  fixed  oil ;  (in  part) 
by  addition  of  dry  chloride  of  calcium,  and  (with  a  little  loss) 
by  repeated  distillations  with  water. — Also  (qualitatively)  by 
adding  to  5  or  10  drops  of  the  oil,  in  a  test-tube,  a  fragment  of 
dry  tannic  acid,  agitating,  and  leaving  several  hours  at  ordinary 
temperature.  In  absence  of  alcohol,  the  tannin  remains  solid, 
porous,  and  floats ;  in  presence  of  alcohol,  it  becomes  pasty  or 
liquid,  and  adheres  to  the  glass  or  sinks  (HAGER). — Farther, 
volatile  oils  may  be  (quantitatively)  separated  from  alcohol  by 
glycerin  (HAGER)  :  In  a  graduated  cylinder  place  10  parts  of  the 
mixture  of  oil  and  alcohol  and  10  parts  of  a  mixture  of  -|  gly- 
cerin and  -^  water,  agitate,  and  set  aside  a  few  hours  for  separa- 
tion. Eead  off  at  about  17.5°  C.  (Oil  of  Balm  is  soluble  in 
glycerin.) — Separation  of  volatile  oils  (or  of  Camphor)  from 
alcohol  may  be  made  by  water  solution  of  nitrate  or  sulphate 
of  sodium  much  more  nearly  than  by  water  alone,  and  for 
approximately  quantitative  purposes.  In  a  flask  with  a  graduated 
neck,  or  a  wide  cylinder  having  its  upper  third  narrowed  and 
graduated,  place  about  3  vols.  of  a  half-saturated  solution  of  the 
salt  and  add  1  vol.  of  the  alcohol  solution  of  oil  or  camphor, 
agitate  thoroughly,  add  enough  of  the  salt  solution  to  adjust  the 
surface  to  graduated  portion  of  the  measure,  and  set  aside  at 
20°  to  25°  C.  until  the  liquids  separate  clear.  The  c.c.  of  oil 
multiplied  by  its  spec.  grav.  equal  the  grams.  For  camphor 
(and  if  desired  for  oils)  the  process  may  be  completed  gravi- 
metrically,  by  adding  about  3  parts  of  exactly  weighed  paraffin, 
fusing  (inserting  a  platinum  hook),  and  weighing  when  cold. 
Compare  67,  c. 


VOLATILE    OILS.  107 

105.    COLOR  AND  SPECIFIC  GRAVITY  OF  VOLATILE  OILS. 


Volatile  Oils. 

Color  of  the  Crude  Oil. 

Color 
after  Rectifica- 
tion. 

Spec.  Grav. 

Amber, 

Yellowish  or  reddish-brown. 

Colorless     or 

0.80—0.88 

yellowish. 

Anise,  . 

Pale  yellow  to  yellow. 

.98—  .99 

Balm,   . 

Yellowish. 

'  .85—  .89 

Bergamot    . 

Yellowish-green  or  brown-yel- 

Colorless    or 

.88—  .95 

low. 

yellowish. 

Bitter  Almond,  . 

Yellowish,  growing  darker. 

1.04-1.06 

Cajeput, 

Green. 

Colorless. 

.91—  .94 

Calamus, 

Pale  yellow. 

.89—  .95 

Camphor  (oil  of). 

Yellowish  to  reddish-brown. 

.94 

Caraway,    . 

Pale  yel'w,  growing  brownish. 

Colorless. 

-.91—  .94 

Cardamom, 

Greenish-yellow. 

.93—  .95 

Cascarilla,  . 

Dark  yellow. 

.90—  .93 

Chamomile, 

Dark  blue. 

.91—  .94 

"    Roman,    . 

Light  blue. 

Cinnamon,  . 

Yellow,  becoming  darker. 

1.03—1.06 

"    (Cassia),    . 

Light  yellow  to  dark  yellow. 

1.03—1.08 

Cloves, 

Bro  wnish-y  ello  w. 

1.03—1.06 

Copaiba, 

Colorless  or  yellowish. 

Colorless. 

.87—  .91 

Coriander,  . 

Yellowish. 

Colorless. 

.87—  .89 

Cubeb, 

Colorless. 

.92—  .94 

Cummin, 

Yellowish. 

.90—  .97 

Dill,      .        .        . 

Yellowish,  becoming  red-br'n. 

.88—  .93 

Eucalyptus, 
Fennel, 
Galbanum,  . 

Colorless. 
Colorless,  growing  yellowish. 
Yellowish. 

.88—  .93 
.90—  .99 
.90—  .92 

Galangal,    . 

Yellowish. 

.91—  .92 

Geranium,  . 

Yellowish. 

.90—  .91 

Hedeoma,    . 

Light  yellow. 

.94 

Hops,   . 

Pale  brownish  yellow. 

.90—  .91 

Jasmin, 

Yellowish. 

Juniper  wood,     . 
"      berries,  . 
Lavender,    . 
Lemon, 

Colorless  or  yellowish-green. 
Colorless,  yel'  wish  or  greenish. 
Colorless,  growing  darker. 
YeUowish. 

Colorless. 
Colorless. 

.84—  .89 
.87—  .90 
.845-  .865 

Mace,   . 

Pale  yellow. 

Colorless. 

.87—  .95 

Marjoram,  . 

Ulear  yellow. 

.89—  .92 

Myrrh, 

Colorless  or  yellowish. 

1.10—1.12 

Nutmeg, 

Pale  yellow,  darkening. 

.90—  .93 

Orange  flowers,  . 
Orange  peel, 

Uolorless,  growing  yellowish. 
Yellowish. 

Colorless. 

.85—  .90 
.83—  .85 

Origanum,  . 

Yellowish  to  brown-yellow. 

.80—  .90 

Parsley, 

Yellowish. 

1.02—1.04 

Pepper  (black),   . 

Yellowish  to  clear-brown. 

.85—  .89 

Peppermint, 

Pale  yellow,  or  greenish  iri- 

descent. 

Pimento  (allspice) 
Rosemary,  . 
Roses,  . 

Dolorless  to  yellowish. 
Colorless  or  pale  yellow-green. 
Colorless,  reddish,  or  yerwish; 

.89—  .92 
.88—  .92 
.83—  .84 

concrete  below  20°  C. 

Rosewood,  . 

Pale  yellow. 

103  NEUTRAL   SUBSTANCES,   LIQUID    OR  FUSIBLE. 

1O5.    COLOR  AND  SPECIFIC  GRAVITY  OF  VOLATILE  OILS.- 
Continued. 


Volatile  Oils. 

Color  of  the  Crude  Oil. 

Color 
after  Rectifica- 
tion. 

Spec.  Grav. 

Rue,     . 

Yellowish. 

.85—  .90 

Sage,    .        . 

Green-yellow  or  yellowish. 

.86—  .92 

Sassafras,    . 

Yellowish  to  red-yellow. 

1.06—1.08 

Savine, 

Colorless  or  yellowish. 

.89—  .93 

Spearmint,  . 

Yellowish,     becoming    dark, 

.91—  .98 

red-brown. 

• 

Tansy, 
Turpentine, 

Pale  yellow  or  green  yellow. 
Colorless. 

.90—  .95 
.87—  .89 

Thyme, 

Yellow-green,  red-brown. 

.87—  .89 

Valerian,     . 

Yellow-brown,  green-brown. 

.90—  .96 

Wintergreen,      . 
Wormseed   (San- 

Reddish. 

Colorless. 

1.14—1.17 

[    tonica), 

Brownish-yellow. 

.91—  .96 

Wormwood, 

Green. 

.88—  .93 

Yarrow, 
Ylang-Ylang,     . 

Dark-blue. 

.87—  .92 
.98 

106.  Solubility  of  Volatile  Oils  in  Alcohol  of  sp.  gr. 
O.822  (90  per  cent:) 

Take,  in  a  test-tube,  from  a  minim  measure,  5  or  10  minims 
of  the  oil,  and  then  as  many  minims  of  the  alcohol  as  required, 
with  agitation,  to  dissolve.  The  oils  which  form  solutions  more 
or  less  turbid  are  given  with  figures  in  heavy  type.  It  will  be 
borne  in  mind  that  oils  are  less  soluble  when  old  than  when 
fresh.  Also,  that  mixtures  of  oils  usually  have  solubilities  mid- 
way between  those  of  the  individual  oils  therein. 

Alcohol  required,  at  17°  to  20°  (7.,  for  1  vol.  of  oil  of 

Amber, 

Anise, 

Balm,  .... 

Bergamot,  . 

Bitter  Almond,   . 

Cajeput, 

Calamus, 

Caraway,    . 

Cardamom, 

Chamomile, 


3#  vols. 

Cinnamon,  . 

.    1     vol 

1 

"        (Cassia),    . 

.    1 

3 

Cloves, 

.    1 

# 

Copaiba, 

.    0 

1 

Cubeb, 

.  25 

11 

Cummin, 

.    1 

1 

Fennel, 

.  Ito2 

iftol 

Juniper  berries, 

.  10 

tf  tol 

Lavender,  . 

.     1 

8 

Lemon, 

.  50        * 

VOLATILE   OILS. 


109 


Mace, 
Marjoram,  . 
Orange  flowers,  . 
Orange  peel, 

.    5    vols. 
.    1        " 
.  Ito2 
.     5 

Rue,     .... 
Sage,    .... 
Savine, 
Tansy, 

.    1    vols 
.    1 
.  Ito2 
1 

Parsley, 
Peppermint, 
Rosemary,  . 
Roses, 

.    3^ 
.    1 
.  Ito2 
50  to  70 

Turpentine, 
"       rectified,  . 
Valerian,     . 
Wormwood, 

.    9 
10  to  12 
.    1 
.    1 

107.  Eeaction  of  Volatile  Oils  with  Iodine  and  Bro- 
mine. (1)  When  about  0.1  gram  of  dry  pulverized  iodine  is 
placed  at  ordinary  temperature  in  a  watch-glass  and  4  or  5  drops 
of  the  oil  are  dropped  upon  it : 

(a)  Giving  instantaneous  reaction,  with  much  heat  and 
strong  effervescence ,'  Oils  of 

Lemon,  Savine, 

Mace,  Turpentine, 

Orange  flowers,  Wormwood  (old). 

Orange  peel, 

slight    heat,  with    gentle    effervescence: 


Bergamot, 
Eucalyptus, 
Hops, 
Lavender, 


(b)  Generating 
Oils  of 

Anise,  Dill, 

Balm,  Fennel, 

Caraway,  Jumper, 

Chamomile,  Marjoram, 
Cubeb, 

(c)  Giving  no  reaction,  or  very  slight, 

Amber,  ,  Cinnamon  (Cassia), 

Bitter  Almond,  Cloves, 

Cajeput,  Mustard, 

Calamus,  Parsley, 

Cascarilla,  Peppermint, 

Cinnamon  (Ceylon),  Roses, 

(2)  Upon  5  or  6  drops  of  the  oil,  on  a  watch-glass,  one  drop 
of  bromine  is  let  fall  (MAISCH). 

(a)  Giving  detonation  with  Oils  of 

Amber,  Juniper  wood, 

Bergamot,  Lemon, 

Hedeoma,  Turpentine. 
Juniper  berries, 


Rosemary, 
Sage, 
Sassafras, 
Thyme. 

Oils  of 

Rue, 

Sassafras, 

Thyme, 

Valerian, 

Wormwood  (fresh). 


110  NEUTRAL   SUBSTANCES,   LIQUID    OR  FUSIBLE. 

(b)  Giving  a  hissing  sound  with  Oils  of 

Anise,  Sassafras, 

Caraway,  Wormseed. 

(3)  To  5  or  6  drops  of  the  oil,  on  a  watch-glass,  add  5  drops 
of  ether  solution  of  bromine  (1  vol.  bromine  to  5  vols.  officinal 
ether,  added  slowly,  while  cooling,  just  before  use).* 

(a)   Vapors  evolved  with  Oils  of 

Copaiba  (green  color  ;  afterward  brownish-green  with  brown  sediment). 

Cubeb  (violet  color,  deepening  ;  afterward  dark  greenish-blue,  with  violet- 
black  sediment). 

Orange  peel  (yellow  color  soon  appears  ;  afterward  pale  brown  and 
transparent). 

Patchouli  (deep  violet  color,  deepening  ;  sediment  dark  brown).  ^ 

Sassafras  (at  first  cloudy  ;  afterward  pale  brownish-yellow). 

Spearmint,  old,  yellowish-red  (color  changes  to  yellowish-brown  ;  sediment 
lighter). 

Wintergreen  (formation  of  a  resinous  white  substance,  spreading  over  the 


(b)  Vapors  not  evolved  with  Oils  of 

Anise  (white  color  ;  with  more  bromine,  yellowish-red). 

Bergamot  (color  greenish-brown  yellow,  then  reddish-brown  yellow). 

Bitter  Almond  (dissolves  without  reaction  ;  after  evaporation  of  the  ether, 

two  liquids  separate — one  deep,  the  other  light  red). 
Cajeput    (supernatant    liquid   scarcely    colored ;    appearance   of    green 

droplets). 

Calamus  (colors  red-brown,  brown-green  ;  finally  a  dark  sediment). 
Caraway  (little  reaction  ;  sediment  yellowish-brown). 
Cinnamon  (color  lemon-yellow,  turning  to  amber-brown). 
Cloves  (color  greenish ;  lower  stratum  alters  to  pale  grayish-black). 
Hedeoma  (color  changed  to  purplish  and  darkened  ;  liquids  not  miscible). 
Lavender  (light  greenish,  darkening  to  deep  sea-green). 
Lemon,  old  (brisk  reaction  ;  colors  reddish-yellow  and  greenish). 
Mustard  (miscible,  colorless  ;  afterward  milk-white). 

*  MAISCH  :  Proc.  Am.  Phar.  A.,  1859,  338. 


VOLATILE   OILS.  Ill 

Nutmeg  (at  first  colorless  ;  the  lower  stratum  then  brownish  and  milky  to 

clear). 

Peppermint  (colors— yellowish,  then  reddish,  then  brown— thickening). 
Rosemary  (colorless  ;  afterward  lower  stratum  is  light-brown). 
Rue  (at  first  cloudy,  then  pale  brownish  yellow). 
Valerian  (at  first  purplish-black  ;  then  upper  stratum  deep  violet,  lower 

greenish-black,  marginal  blue  and  red  spots). 
Wormseed  (reaction  is  slow ;  heavier  liquid  red  to  brown ;  lighter  liquid 

light  brown  and  almost  clear). 
Wormwood  (darkens  a  little  without  movement). 

108.  Reaction  of  Volatile  Oils  with  Sulphuric  Acid 
and  Alcohol  (HAGER'S  Method).  In  a  test-tube  of  about  1.3 
centim.  (0.5  inch)  diameter,  5  or  6  drops  of  the  oil  are  agitated 
with  25  to  30  drops  of  concentrated  sulphuric  acid,  after  which 
it  is  noted  how  much  heat  and  how  much  turbidity,  if  any,  have* 
been  produced.  When  the  liquid,  if  heated,  has  cooled  again, 
8  or  10  c.c.  of  90  per  cent,  alcohol  are  added,  with  brisk  shaking 
while  the  test-tube  is  closed  by  the  finger.  Now  the  production 
of  celor  and  of  turbidity  are  noted.  In  case  of  turbidity,  after 
standing,  a  subsident  layer  usually  appears,  having  a  character- 
istic color,  and  being  soluble  in  cold  or  in  hot  alcohol  or  in 
chloroform. 

(a)  The  mixture  of  oil  with  acid  and  alcohol,  is  clear  and 
transparent,  or  ~but  very  slightly  turbid,  in  case  of  Oils  of 

Amber  (with  sulphuric  acid,  not  heated,  dark  yellow  and  turbid  ;  after  add- 
ing alcohol,  yellow,  slightly  turbid,  made  clear  by  boiling). 

Anise  (with  the  acid,  in  part  dark  red  and  thick,  and  in  part  clear  and  lim- 
pid ;  with  the  alcohol  the  thick  part  remains  dark  and  undissolved, 
while  the  liquid  part  is  clear  and  nearly  colorless). 

Bitter  Almond  (with  the  acid,  a  brown  color  and  much  heat  without  turbi- 
dity ;  with  the  alcohol,  a  clear  and  nearly  colorless  mixture). 

Cloves  (with  the  alcohol,  the  mixture  is  nearly  or  quite  clear). 

Dill  (with  acid,  generation  of  heat  and  vapors,  with  dark  yellow-red  color 
and  some  turbidity  ;  with  alcohol,  a  pale  cinnamon-brown  mix« 
ture,  nearly  or  quite  clear — fully  clear  on  boiling). 


112  NEUTRAL   SUBSTANCES,   LIQUID    OR  FUSIBLE. 

Fennel  (with  acid,  heat  and  vapors,  the  mixture  dark  red  and  pretty  clear  ; 

with  alcohol,  yellowish,  clear  solution). 
Mustard  (with  acid,  very  little  heat,  yellowish  tint,  clear  ;  with  alcohol, 

colorless  and  clear). 

Nitrobenzole  or  "artificial  oil  of  bitter  almonds  "  (without  turbidity). 
Peppermint,  best  (with  the  acid,  slight  heat  and  yellow-red  color  ;  with  the 

alcohol,  light  red,  slightly  turbid  mixture,  made  clear  by  boiling). 
Peppermint,  American  .(with  the  acid,  heat  and  dark  brown-red  color  ; 

with  the  alcohol,  brownish  and  turbid,  made  clear  by  boiling). 
Roses  (with  acid,  heat,  thick  vapors,  and  dark  brown-red  color  ;  with  alco- 
hol, brown,  clear,  and  transparent). 
Valerian  (with  the  acid,  heat  and  slight  vaporization,  dark  red  color,  slight 

turbidity  ;  with  the  alcohol,  red,  turbid,  but  rendered  clear  by 

boiling). 

(fj)  The  mixture  of  oil  with  acid  and  alcohol  is  left  more  or 
less  turbid,  in  case  of  Oils  of 

Balm  (with  acid,  heat,  vapors,  brown-red  color,  and  turbidity  ;  with  alco- 
hol, cinnamon-brown,  somewhat  turbid  ;  after  boiling  becomes 
clear  with  separation  of  dark  drops). 

Bergamot  (with  acid,  heat  and  vapors  ;  the  alcohol  solution  pale  grayish- 
yellow  turbid,  with  flocculent  separate  after  shaking ;  after  one  or 
two  days,  the  residue  is  but  slight  and  divisible  on  shaking,  the 
liquid  being  clear  yellow). 

Cajeput  (with  acid,  heat  and  vapors,  light  yellow  color  and  turbidity  ;  with 
alcohol,  pale  rose-gray  turbidity,  made  clearer  by  boiling). 

Caraway  (with  acid,  heat  and  vapors,  dark  yellow  to  red-brown  color,  tur- 
bidity ;  with  the  alcohol,  a  red  and  turbid  mixture,  made  nearly 
clear  by  boiling). 

Cascarilla  (with  acid,  heat  and  vapors,  dark  brown-red  color,  turbidity  ; 
with  alcohol,  the  same  ;  an  hour  after  boiling,  dark  brown-violet 
to  bluish-red). 

Cinnamon  (Cassia)  (with  acid,  a  strong  heat  and  vaporization,  dark  black- 
brown,  very  thick  mixture  ;  after  the  alcohol,  the  dark  viscid 
mass  remains  mostly  insoluble,  with  a  milky  olive-green  liquid 
above). 


VOLATILE    OFL&  113 

Copaiba  (with  the  acid,  heat  and  vapors,  the  color  dark  yellow-red,  with 

turbidity  ;    with  alcohol,   red  and    turbid,   not  made  clear  by 

boiling). 
Coriander  (with  sulphuric  acid,  heat  and  vapors,  dark  red  color,  scarcely 

turbid  ;  with  alcohol,  dark  brown,  with  green  shade,  and  turbid). 
Eucalyptus  (with  sulphuric  acid,  heat  and  vapors,   light  reddish-yellow 

color,  with  turbidity  ;  with  alcohol,  very  turbid,  with  whitish- 
peach-blow  or  pale  rose-gray  color). 
Geranium  (with  acid,  much  heat  and  thick  vapors,  turbid,  dark  yellow-red ; 

with  alcohol,  turbid  and  dark  brown  ;  after  boiling,  turbid  and 

red-brown). 
Juniper  berries  (with  acid,  heat  and  vapors,  turbid,  dark-yellow-red  ;  after 

the  alcohol,  very  turbid,  sometimes  flocculent,  of  blackish-rose 

color  ;  after  boiling,  turbid  ;  after  a  few  hours,  a  light-colored 

resinous  mass  separates). 
Juniper  wood  (with  acid,  heat  and  vapors,  turbid,  orange-red  ;  with  alcohol," 

pale  yellowish,  turbid  before  and  after  boiling). 
Lavender  (with  acid,  heat  and  vapors,  turbid  and  brown-red  ;  with  alcohol, 

turbid,  dark  brown  with  green  tint). 
Lemon  (like  Bergamot  oil  :  after  one  or  two  days,  the  slight  residue  forms 

opaque  yellow  drops  not  divisible  by  shaking). 
Mace  (with  acid,  heat  and  vapors,  turbid,  dark  red  ;  with  alcohol,  turbid 

and  dark  reddish-brown,  not  made  clear  by  boiling). 
Marjoram  (with  acid,  heat  without  vapors,  turbid  and  yellow-red  ;  with 

alcohol,  very  turbid,  peach-blow  and  almost  milky  ;  turbid  after 

boiling). 
Orange  flowers  (with  acid,  heat  and  vapors  ;  after  alcohol,  turbid  and  brown, 

approaching  red  ;  after  boiling,  a  little  darker  and  less  turbid). 
Orange  peel  (with  acid,  a  strong  heat,  turbidity  and  red-brown  color  ;  with 

alcohol,  whitish-yellow;  turbid  before  and  after  boiling). 
Parsley  (with  acid,  a  moderate  heat  and  a  little  vapor,  very  dark  red  ;  with 

alcohol,  very  turbid,  red,  with  swimming  flocks). 
Rosemary  (with  acid,  strong  heat  but  no  vapors,  yellow-red  and  turbid  ; 

with  alcohol,  milky  turbid  ;  turbid  after  boiling). 

Rue  (with  acid,  heat  and  vapors,  dark  red,  turbid  ;  with  alcohol,  raspberry- 
red,  turbid  ;  clear  after  boiling). 
Sage  (like  Oil  of  Rue). 


114  NEUTRAL   SUBSTANCES,   LIQUID    OR   FUSIB1:E. 

Savine  (with  acid,  strong  heat  without  vapors,  moderately  tu.-bid,  dark  red; 
with  alcohol,  turbid,  reddish-clay-colored  ;  after  boiling,  less  tur- 
bid, pale  red). 

Tansy  (with  acid,  heat  and  vapors,  dark  red,  turbid  with  alcohol,  yellow- 
red,  less  turbid  ;  after  boiling,  clear). 

Thyme  (with  acid,  heat  and  vapors,  red,  turbid  after  alcohol  ;  after  boiling, 
clear,  with  swimming  oil-drops). 

Turpentine  (deviating  greatly  from  differences  of  production  and  of  age). 

Wormseed  (Santonica)  (with  acid,  moderate  heat  and  vapors,  dark  red,  tur- 
bid ;  with  alcohol,  cinnamon-brown,  turbid  ;  becoming  clear  on 
boiling). 

Wormwood  (with  acid,  heat  and  vapors,  red-brown,  turbid  ;  with  alcohol, 
dark,  green-violet,  opaque,  turbid  ;  becoming  clear  with  more 
alcohol). 

Ylang-Ylang  (with  acid,  heat  and  vapors,  turbid  and  dark  red  ;  with  alco- 
hol, pale  brick-red  and  very  turbid,  less  turbid  after  boiling). 

109.  Eeaction  of  Volatile  Oils  on  Sulphide-of-Lead- 
Paper  (G.  WILLIAMS).     Blotting-paper   is   wetted   in   a   dilute 
alcoholic  solution  of  acetate  of  lead  and  dried  in  an  atmosphere 
of  hydrosulphuric  acid.     A  few  drops  of  the  oil  are  let  fall  on 
a  strip  of  this  paper,  which  is  placed  in  a  (dry)  dark  place  for 
5  or  10  or  15  hours,  when  the  degree  of  bleaching  is  noted. 

The  paper  is  bleached  by  Oils  of  Lavender,  Peppermint, 
Eosemary,  Turpentine.  The  paper  is  not  bleached  by  Oils  of 
Anise,  Bergamot,  Cajeput,  Cinnamon,  Juniper  berries,  Lemon, 
Orange  peel,  Sage,  Thyme. 

110.  Reaction  of  Volatile  Oils  with  Sodium  (DRAGEN- 
DORFF).     The  Hydr3carbons  are  not  affected;  the  Oxidized  oils 
are  more  or  less  readily  decomposed.     Ten  drops  of  the  oil  are 
treated  with  a  small  piece  of  the  metal.    The  result  is  discovered 
after  5  or  10  minutes.     (Alcohol  causes  a  prompt  reaction,  with 
evolution  of  hydrogen.)     Little  or  no  change  occurs  with  Oils 
of   Amber,   Bergamot,    Copaiba,    Lavender,  Lemon,    Nutmeg, 
Pepper,  Peppermint,  Rosemary,  Sage,  Turpentine.     Oil  of  Mus- 
tard evolves  hydrogen. 


VOLATILE   OILS.  115 

111.  Identification  of  Resinified  or  Old  Oils,  or  of 

Resins  or  Fixed  Oils  in  mixture  with^  volatile  oils.  Evaporate 
1  gram  of  the  oil,  on  a  tared  watch-glass,  at  70°  to  90°  C.  (or 
over  the  water-bath).  Fresh  and  unchanged  oils,  free  from  mix- 
ture, leave  only  a  scarcely  perceptible  and  not  weighable 
residue. 

This  residue,  fully  freed  from  volatile  oil,  may  be  tested  for 
Castor  Oil,  by  treatment  for  cenanthyc  acid,  as  described  under 
Ricinoleic  Acid  (46). 

112.  Identification    of   Turpentine    Oil.     The    sparing 
solubility  of  this  oil  in  aqueous  alcohol  affects  its  mixtures  with 
other  oils,  but  does  not  enable  it  to  be  separated.     The  alcohol 
should  be  75  to  90  per  cent. — HEPPE'S  test  is  with  nitroferri- 
cyanide  of  copper — prepared  by  precipitating  solution  of  sulphate 
of   copper  with   solution   of    nitroferricyanide    of   sodium,   and 
washing  and   drying  the  precipitate.     In  a  test-tube  place  a  bit 
of  this  reagent  as  large  as  a  pea,  then  about  25  drops  of  the  oil, 
and  heat,  so  as  finally  to  boil  for  a  few  seconds,  and  set  aside  to 
subside.     Turpentine  oil  (also  lemon  oil)  does  not  suffer  change, 
or  more  than  slight  change — while  the  sediment  of  nitroferricy- 
anide is  green  or  blue-green.     Other  volatile  oils  are  darkened 
to  different  colors ;  while  the  sediment  of  copper  salt  is  gray, 
brown,  or  black. 

113.  Identification  of  Valerian  Oil.     One  drop  of  the  oil 
is  dissolved  in   15   drops  of  bisulphide  of  carbon,  then  shaken 
with  sulphuric  acid,  and  afterward  one   drop  of  nitric  acid,  of 
spec.'grav.  1.2,  is  added.     A  fine  blue  color  results  when  even 
slight  portions  of  the  oil  are  present  (FLUCKIGER). 

114.  Identification    of   Oil   of  Peppermint.     50  to   70 
drops  of  the  oil,  with  1  drop  of  nitric  acid,  of  spec.  grav.  1.20, 
turns  faintly  brownish,  and  after  an  hour  or  two  becomes  fluores- 
cent— blue-violet  or  green-blue  by  transmitted  and  copper-color 
by   reflected  light    (FLUCKIGER). — Chloral-  hydrate,   on    contact 
with  oil  of  peppermint,  colors  it  reddish..    The  tint  deepens  to 
cherry-red,  is  intensified  by  sulphuric  acid,  and  varied  to  dark 


116  NEUTRAL  SUBSTANCES,  LIQUID   OB  FUSIBLE. 

violet  by  chloroform.     (No  color  is  obtained  with  oils  of  lemon, 
bergamot,  juniper,  rosemary,  cloves,  anise,  or  fennel.) 

For  qualitative  separation  of  Benzole  from  volatile  oils,  see 
119;  of  Nitrobenzole  from  Bitter  Almond  Oil,  see  120. 

115.  CAMPHOR.    C10H16O.    Laural  Camphor. — A  slightly 
unctuous,  pellucid  solid,  friable  with  cleavage,  of  specific  gravity 
0.985  to  0.996;  melting  at  142°  C.  (288°  F.),  slowly  vaporizable 
at  ordinary  temperatures,  condensing  in  hexagonal  plates,  boiling 
at  204°  C.  (400°  F.)     It  is  soluble  in  1,000  parts  of  water  applied 
by  ordinary  contact,  or  in  150  to  200  parts  of  water  by  tritura- 
tion  with  an  insoluble  powder ;  freely  soluble  in  alcohol,  ether, 
chloroform,  benzole,  petroleum  naphtha,  methylic  alcohol,  amylic 
alcohol,  creosote,  acetic  acid,  mineral  acids,  bisulphide  of  carbon, 
fixed  and  volatile  oils,  and  forms   a  liquid  mixture  with  solid 
chloral   hydrate. — Minute  particles  of  camphor,  dropped  upon 
water,  rotate,  with  velocity  in  proportion   to   their  smallness. 
If  an  oiled  pin-point  is  then  touched  to  the  water,  the  rotations 
are    stopped,    and    the    camphor    particles    carried   out    by   the 
enlarging  circular  oil-film. 

By  prolonged  boiling  with  concentrated  nitric  acid  or  per- 
manganate of  potassium,  camphor  is  changed  into  Camphoric 
Acid.  The  latter  is  sparingly  soluble  in  water,  from  which  it 
crystallizes  in  colorless  scales  or  needles,  of  sour  and  bitter 
taste,  melting  at  70°  C.,  and  forming  insoluble  salts  with  lead 
and  many  other  metals. — By  heating  in  a  closed  vessel  with 
bromine,  Bromated  Camphor  is  formed,  as  a  crystallizable  solid, 
not  soluble  in  water. 

116.  CREOSOTE.     Chiefly  Creosol,  C8H10O3,  and  Guaiacol, 
C7H8O2.     An  oily  limpid  liquid,  of  spec.  grav.  1.060  to  1.085, 
colorless  or  yellowish  (growing  brownish  in  the  light),  boiling  at 
200°  to  206°  C.  (392°  to  403°  F.),  having  a  neutral  reaction,  a 
strong  and  persistent  smoky  odor,  and  a  very  caustic  and  smoky 
taste.     It  is  soluble  in  60  to  90  parts  of  water,  in  all  proportions 


CREOSOTE.      ANTHRACENE.      ALIZARIN.  117 

of  alcohol,  ether,  chloroform,  benzole,  petroleum  naphtha,  fixed 
and  volatile  oils,  anhydrous  glycerin,  acetic  acid,  sulphuric  acid 
(with  combination  and  brown  color),  and  in  an  equal  part  of 
bisulphide  of  carbon.  It  is  soluble  in  aqueous  alkalies — forming 
instable  salts.  It  dissolves  (and  in  commerce  usually  contains) 
about  8  per  cent,  of  water,  from  which  it  is  separated  by  mixture 
With  a  large  quantity  of  benzole. 

Creosote  resembles  Phenic  Acid,  in  most  of  its  physical 
properties,  and  in  its  reactions  with  nitric  acid,  ferric  salts,  bro- 
mine, gelatin,  and  albumen.  It  is  distinguished  from  Phenic 
acid  by  not  crystallizing  when  pure ;  by  gelatinizing  collodion; 
by  not  giving  a  blue  color  with  ferric  salts  in  a  slightly  alcoholic 
and  sufficiently  dilute  solution  of  ferric  chloride,  as  specified 
under  Phenic  acid,  35,  c  (Fluckiger's  test) ;  by  not  forming  a 
clear  mixture  with  a  double  volume  of  18  to  20  per  cent,  ammo- 
nia, or  with  5  volumes  of  ordinary  (slightly  aqueous)  glycerin, 
or  with  a  greater  volume  of  bisulphide  of  carbon;  and  by 
more  sparing  solubility  in  water, 

117.  ANTHRACENE.     C14H10.     A    colorless   solid,    crys- 
tallizing   in   the   monoclinic  system,  often  in  four  or   six-sided 
tablets,  having  spec.  grav.  1.147,  melting  at  about  212°  C.,  sub- 
liming slowly  from  the  solid,  and  distilling  rapidly  at  300°  C. 
When  pure,  the  crystals  show  blue  or  violet  fluorescence.     It  is 
tasteless  and  odorless,  but  its  vapor  at  the  distilling  point  is  dis- 
agreeable   and   irritating. — It    is   insoluble    in   water,   sparingly 
soluble  in  cold,   moderately  soluble   in  hot  alcohol,  soluble  in 
ether,   benzole,   and   oil    of    turpentine. — It   is    not    affected   by 
alkalies  ;  is  acted   on  by  nitric  acid,  and  dissolved  with  green 
color  by  sulphuric  acid.     With  picric  acid,  in  saturated  alcoholic 
solution,  it  forms  a  salt  crystallizing  in  red  needles. 

118.  ALIZARIN.     C14H8O4.     A  yellow  to  red-yellow  solid ; 
by    sublimation    (at   215°    C.)    crystallizing   anhydrous    in   red 
prisms,  and  from  solutions  crystallizing  in  golden  scales  of  the 


118  NEUTRAL   SUBSTANCES,   LIQUID    OR   FUSIBLE. 

hydrate. — Slightly  soluble  in  water ;  soluble  in  alcohol  and  ether 
(with  yellow  color)  and  in  concentrated  sulphuric  acid  (with 
brown  color) ;  soluble  in  aqueous  alkalies  and  alkaline  carbonates 
(with  purple  color) ;  these  solutions  being  precipitated  (orange) 
by  acids,  in  good  part  even  by  carbonic  acid  gas.  The  ammo- 
niacal  solution,  with  salts  of  magnesium,  iron,  copper,  and  silver, 
forms  purple  and  iridescent  precipitates ;  the  potassa  solution  is 
decolorized  by  lime-water,  and  the  alcohol  solution  is  decolorized 
by  alumina  with  formation  of  a  red  precipitate. 

119.  BENZOLE.  C6H5H  with  traces  of  its  homologues. 
Coal-tar  naphtha.  Benzene. — A  colorless  limpid  liquid,  of  about 
0.85  spec,  grav.,  crystallizing  at  0°  C.,  melting  at  5.5°  C.a  boiling  at 
80°  or  81°  C.  (176°  or  178°  F.),  and  of  a  characteristic  pleasant 
odor,  reminding  of  rose  and  of  chloroform.  It  burns  with  a  bright, 
smoky  flame.  It  is  not  perceptibly  soluble  in  water  (to  which, 
however,  it  imparts  odor),  but  is  soluble  in  all  proportions  of 
alcohol,  ether,  chloroform,  petroleum  naphtha,  etc.  It  dissolves 
sulphur,  phosphorus,  iodine,  fixed  and  volatile  oils,  camphors; 
many  resins  (see  99,  f);  many  alkaloids  (not  cinchonia)  (133). 

It  is  distinguished  from  Petroleum  Naphtha  by  its  generally 
greater  solvent  power  (by  dissolving  hard  pitch),  and,  more 
accurately,  by  its  formation  of  nitrobenzole  and  products  of  the 
latter,  as  follows :  Equal  volumes  of  nitric  acid  of  spec.  grav. 
of  1.5  or  of  concentrated  nitric  acid  containing  nitrous  acid,  and 
of  the  liquid  tested  for  benzole,  are  digested  in  a  test-tube  by 
immersion  in  hot  water.  The  nitrobenzole  rises  in  droplets,  and 
is  recognized  by  its  odor  of  bitter  almond  oil  and  by  its  giving 
anilin  with  reducing  agents,  as  stated  at  120. 

Or,  for  more  delicate  test — as  in  presence  of  Volatile  Oils  : 
A  few  drops  of  the  liquid  to  be  tested  are  mixed  in  a  cooled 
tube  with  four  times  their  volume  of  fuming  nitric  acid  ;  the 
mixture  is  agitated  and  left  a  quarter  of  an  hour ;  then  mixed 
with  ten  times  its  bulk  of  water  (which  separates  drops  of  nitro- 
benzole). Agitate  with  ether,  which  takes  up  the  nitrobenzole ; 


PETROLEUM  NAPHTHA.      NITROBENZOLE.  119 

decant  the  ether  solution,  filter,  quickly  distil  the  ether  from  the 
filtrate.  To  the  residue  add  1  or  2  c.c.  of  acetic  acid  and  a 
particle  of  iron  (filings),  and  distil  over  a  very  small  flame.  As 
soon  as  the  liquid  is  nearly  evaporated,  add  2  or  3  c.c.  of  water 
and  distil  again.  Mix  the  distillates  (if  acid,  neutralize  with 
slaked  lime  and  filter),  and  test  with  chlorinated  lime  for  anilin 
^violet  color)  (125,  a). 

119J.  PETROLEUM  NAPHTHA.  Gasolene.  "Ben- 
zene."— The  rectified  distillate  of  petroleum,  having  a  boiling 
point  of  about  49°  C.  (120°  F.) — specific  gravity  about  0.665. 
Consists  chiefly  of  C  H  H,  with  a  little  C  H  H  and  other 

«/  511'  613 

homologues. — Characterized  by  an  agreeable  odor  and  anaesthetic 
-effect ;  by  a  wide  range  of  solubilities ;  and  by  resisting  the 
action  of  alkalies  and  most  acids,  while  decomposed  by  heating 
with  nitric  acid. — Distinguished  from  Benzole  by  a  lower 
specific  gravity  (even  when  both  are  of  the  same  boiling  point), 
and,  more  accurately,  by  not  forming  nitrobenzole  (119). 

120,  NITROBENZOLE.  C6H5(NO2).  « Essence  of  Mir- 
bane."  "  Artificial  oil  of  bitter  almonds."  Nitrobenzene. — A 
yellowish,  oily  liquid,  of  spec.  grav.  1.21,  crystallizing  below 
3°  C.,  and  boiling  at  220°  C.  (428°  F.)  Jt  has  the  odor  of  bitter 
almond  oil,  with  equal  persistence  ;  a  very  sweet  taste,  and  a 
highly  poisonous  effect  taken  by  inhalation  or  through  the 
mouth. — It  is  insoluble  in  water,  freely  soluble  in  alcohol,  ether, 
chloroform,  fixed  and  volatile  oils. — It  is  identified  by  its  odor — 
coinciding  with  its  reaction  for  anilin.  When  a  few  drops  are 
digested  in  a  test-tube  with  zinc,  acetic  acid,  and  iron  or  magne- 
sium wire,  and  the  mixture  extracted  with  ether,  the  residue  of 
the  latter  gives  reactions  for  anilin.  See  Benzole  (119)  and 
Anilin  (121).  Or  a  few  drops  are  digested  and  shaken  with  zinc 
and  dilute  sulphuric  acid,  the  mixture  filte?^ed  through  a  wet 
filter,  and  the  filtrate  tested  (with  chlorate  of  potassium)  for 
anilin.  Both  the  above  methods  are  applicable  in  pre$»encA  *>f 


120  BASES,    VOLATILE. 

Bitter  Almond  oil ;  also  the  following :  Two  or  three  cubic  cen- 
timetres of  the  oil  to  be  tested  for  nitrobenzole  are  agitated  with 
about  half  its  weight  of  fused  potassa.  If  nitrobenzole  is 
present,  a  reddish-yellow  color  appears,  quickly  turning  to  green, 
and  if  water  is  added  there  is  separation  of  an  upper  layer  of 
green,  turning  red  the  following  day.  Finely-divided  zinc  or 
iron,  alone,  digested  at  100°  C.  for  a  day  or  two,  reduces  nitro- 
benzole to  anilin. — Nitrobenzole  is  distinguished  from  bitter 
almond  oil  and  other  Volatile  Oils  by  its  specific  gravity. 


BASES:    LIQUID   AND    SOLID. 

121.  ANILIN.        (C6H5)H3N.       Monophenylamin. — Pure 
anilin  is  a  colorless,  limpid,  oily  liquid,  of  spec.  grav.  1.028, 
vaporizing  slightly  at  ordinary  temperatures,  boiling  at  182°  C. 
It  is  neutral  to  litmus,  of  bitter,  burning  taste,  and  vinous,  aro- 
matic odor.     It  is  slightly  soluble  in  water — the  solution  having 
a  faint  alkaline  reaction ;  also  it  dissolves  a  little  water.     It  is 
soluble  in  all  proportions  of  alcohol,  ether,  chloroform,  and  most 
fixed  and  volatile  oils,  and  in  about  equal  volumes  of  bisulphide 
of  carbon  or  benzole,  but  not  perfectly  in  greater  volumes  of 
either.     It  is  sparingly  soluble  in  glycerin. 

122.  The  ANILIN  OIL  OF  COMMERCE  contains  more  or  less 
Toluidin,  with  traces  of  benzole,  phenic  acid,  nitrobenzole,  acetic 
acid,  acetone,  etc.     "  Kuphanilin  "  contains  about  90  per  cent,  of 
phenylamin,  and  has  a  boiling  point  of  180°  to  190°  C.     "  Bara- 
nilin "  is  mostly  toluidin,  with  a  little  cumidin  and  cymidin, 
boiling  at  195°  to  215°  C.* 

*  (Mono)phenylainin, (Ce  Hs )  H2  N. 

Toluidin, (C:  H7 )  Hs  K 

Xylilin, (C8H9)H2N. 

CumidiB, (C9Hii)H2N. 


ANILIN.  12 

123.  Phenylamin  with  acids  forms  salts,  crystallizable, 
soluble  in  water  and  in  alcohol,  many  of  them  soluble  in  ether. 
The  oxalate  is  sparingly  soluble  in  cold  absolute  alcohol,  insoluble 
in  ether ;  the  hydrochlorate  is  soluble  in  ether,  not  in  cold  chlo- 
roform.    Anilin  salts  are  readily  decomposed  by  fixed  alkali,  j 
when  the  anilin  may  be  separated  by  ether.     In  the  cold,  anilin  is 
displaced  by  ammonia ;  with  heat,  ammonia  is  displaced  by  anilin. 

124.  TOLUIDIN   has,  with  most   solvents,  nearly  the  same 
solubility   as  phenylamin.     It  forms  few  salts ;    the  oxalate  is 
sparingly  soluble  in  water. 

125.  Anilin  is  identified,  through  formation  of  Anilin  Red 
(rosanilin,  fuchsin,  or   magenta),  by  chlorinated   lime  or  chlo- 
rinated soda  (a),  by  ferric  chloride  (5),  by  binoxide  of  manga- 
nese and  sulphuric  acid  (c)  ;  and  by  its  reaction  with  chlorate  of 
potassium    and   hydrochloric   or   sulphuric  acid   (d),  and  with 
mercuric    chloride    (e).     It   is   distinguished  from,   Alkaloids 
(including  Conia  and   Nicotia)   by  giving  no  precipitates  with 
potassio  mercuric  iodide  solution,  or  with  iodine  in  iodide  of 
potassium  solution,  or  picric  acid  in  presence  of  sulphuric.     It 
coincides  with  Alkaloids  in  giving  precipitates  with  phosphomo- 
lybdate  (f),  and  with  tannic  acid  (g). — It  is  characterized  by  a 
moderate  reducing  power  (h).     Anilin  is  examined  as  regards 
its  proportion  of  Toluidin,  as  explained  in  a.     It  is  separated 
from  benzole,  nitrobenzole,  and  other  associated  impurities  by 
fractional  distillation. 

Anilin  Red  is  a  term  for  various  salts  and  compounds  of 
ROSANILIN  (CaoH19N3  .H2O).  This  is  a  triatomic  base  which  is 
colorless  when  pure — in  the  air  becoming  rose-red,  or  if  formed 
in  part  from  toluidin  becoming  brown,  also  dissolving  freely  in 
alcohol  with  a  red  color.  It  is  nearly  insoluble  in  water  and 
insoluble  in  ether.  It  forms  mono-acid  salts  having  an  intense 
crimson  color  (in  solution),  and  tri-acid  salts  of  yellowish-brown 
color. — As  formed  from  commercial  anilin,  by  oxidizing  agents, 
rosanilin  has  a  rich  violet-purple  color,  changed  to  red  by  acids, 
and  restored  to  violet-purple  by  alkalies.  In  proportion  as 


122  BASES,    VOLATILE. 

formed  from  toluidin,  the  color  becomes  brown.  Ether  extracts 
the  brown,  leaving  a  blue. 

a.  A  water  solution  of  anilin  or  its  salts,  with  a  little  solution 
of  chlorinated  lime  or  chlorinated  soda  gives  a  purple-red  color, 
changing  to  brown-red  by  exposure  to  the  air,  or  to  rose-red  by 
addition  of  acids.  The  color  passes  into  a  brown ;  if  the  mixture 
be  shaken  with  ether,  the  latter  rises  to  the  surface  as  a  brown 
layer,  leaving  a  blue  liquid  below. 

t>.  To  a  small  portion  (10  c.c.)  of  a  very  dilute  solution  of 
anilin,  strongly  acidulated  with  hydrochloric  acid,  add  of  a  concen- 
trated solution  of  ferric  chloride  two  or  three  drops,  or  enough 
to  give  a  yellowish  tint,  and  heat  gradually  to  boiling.  The 
color  becomes  darker  to  opaque  violet-brown.  When  a  precipitate 
separates,  filter  and  wash  with  water ;  then  treat  the  precipitate 
with  60  per  cent,  alcohol,  when  the  violet  color  is  dissolved.  The 
aqueous  filtrate,  shaken  with  chloroform,  forms  two  light  red  layers. 

c.  A  diluted  solution  of  anilin,  acidulated  with  sulphuric  acid, 
on  agitating  with  binoxide  of  manganese,  quickly  gives  a  blue  to 
purple  red  color,  more  intense  after  warming  to  50°  or  60°  C. 

d.  Chlorate  of  potassium  with  hydrochloric  or  sulphuric  acid, 
when  strong,  forms  a  red  resinous  substance;  when  dilute,  a 
violet  color. 

e.  Mercuric  chloride,  in  the  solid  state,  gently  heated  with 
anilin,  converts  it  into  a  dark-purple  mass  which  gives  a  red 
solution  in  alcohol. 

f.  Phosphomolybdate  of  sodium  with  solutions  of  anilin  aci- 
dulated  with  sulphuric  or  oxalic  acid,  gives  a  blue  precipitate 
becoming  yellow  (with  Nicotia,  the  precipitate   is  yellowish  at 
first).     Addition  of  ammonia  of  18  or  20  per  cent,  dissolves  the 
anilin  precipitate  with  deep  blue  color   (the  Conia  precipitate  is 
left  blue  but  undissolved  by  ammonia). 

g.  Tannic  acid,  with  solutions  of  anilin  not  very  dilute  and 
not  containing  free  acid  or  free  ammonia,  a  white  precipitate  of 
tannate  of  anilin. 

h.  Anilin  reduces   permanganate  solution    buf   no* 
cupric  sulphate. 


CONIA — TRIMETHYLAMIA.  123 

126.  ALKALOIDS.  — Volatile    and   'Non-volatile.—  The 
volatile  alkaloids  are. composed  of  C,  H,  and  N,  without  O ;  and, 
in  their  consistence,  vaporization,  and  other  physical  properties, 
resemble  the  volatile  oils,  but  differ  from  them  by  approaching 
the  character  of  ammonia.     They  are  expelled  from  their  salts 
by  fixed  alkalies  and  heat.     The  most  important  are  the  five 
following.     (For  Solubilities,  see  133;  Separations,  134;  Com- 
parative reactions,  131  and  135  to  143.) 

ANILIN  (121). 

127.  CONIA.*     C8H16!N".     A   colorless  liquid,  of  spec.-  grav. 
0.89,  wasting  slightly  at  ordinary  temperatures,  distilling  almost 
wholly  with  steam  at  100°  C.,  boiling  at  160°  to  180°  C.     It  has 
a  mouse-like  odor,  sharp  taste,  and  strong  alkaline  reaction.     It 
resinifies,  yellowish,  in  the  air.     Its  administration  causes  enlarg- 
ment  of  the  pupil.     It  is  a  strong  base ;  its  salts  being  soluble 
in  water  and  alcohol,  not  in  ether.     It  coagulates  albumen. 

128.  LOBELINA.     An  oily,  volatile  liquid,  of  alkaline  reac- 
tion.    Its  administration  dilates  the  pupils. 

129.  NICOTIA.     C&H7K".     A  transparent,  oily  liquid,  of  spec, 
grav.  1.048,  distilling  with  steam  at  100°  C.,  or  slowly  alone  at 
146°  C.,  boiling  at  243°  C.     It  has  an  ethereal,  tobacco-like  odor 
(when  pure),  and  (in  dilute  solution !)  an  acrid  taste.    In  reaction 
it  is  strongly  alkaline.     It  resinifies  in  the  air. 

130.  TRIMETHYLAMIA.     C3H9N.     Propylamin.     Secalin. — A 
colorless  liquid  below  5°  C.,  its  vaporizing  point.     (Soluble  in 
water  and  alcohol.)     It  has  an  odor  of  herring  and  of  ammonia, 
a  sharp,  bitter  taste,  and  an  alkaline  reaction.     Its  salts  are  crys- 
tallizable,   and   soluble   in  water   and   (mostly)  in  alcohol.     Its 
hydrochlorate   is   soluble   in   absolute   alcohol   (separation   from 
Ammonia).     Its  water  solution  precipitates  aluminum  salts  and 
then  dissolves  the  precipitate  (distinction   from   Ammonia).     Its 
solution  in  equal  weight  of  water  is  combustible. 

*  The  termination  a  is  given  in  this  work  to  all  the  alkaloids,  but  the 
terminal  n  is  used  by  many  writers. 


324 


BASES,    VOLATILE. 


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COMPOSITION ;    CRYSTALLINE  FORM;    COLOR.          125 

132.  Non-volatile  Alkaloids  and  accompanying  Glucosides. 
(For  Solubilities,  133;  Separations,  134;  Reactions  common  to 
alkaloids,  135,  142,  143.)  (For  Determinations  of  Quantity. 
135«,  142,  143.) 

ACONITA.     C30H47NO7. — Glacial  mass  or  white  powder.     Crys- 
tallizes with  difficulty.— 136  (135,  e,  /). 

ATROPIA.  )  C17H23NO3. — Prisms;  stellated  tufts ;  white  powder ; 
DATURIA.  [      fusible  at  90°  C.— 136,  135. 
BERBERINA.     C21H19]N"O6(H2O)5. — Light-yellow  silky  needles,  or 

grouped  prisms. — 136,  138. 
BRUCIA.     C23H26N2O4. — Colorless ;    delicate  needles  ;    four-sided 

prisms.— 136,  137,  138,  140,  139. 
CAFFEINA.     C4H5W2O. — White,  silky  needles ;  fusible  at  178°  C. ; 

subliming  at  185°  C.— 136,  140  (135,  a,  e,  g). 
CINCHONIA.     C20H24N2O. — Four-sided  prisms  or  needles  ;  fusible 

at  165°  C.— 136. 
CINCHONIDIA.     C20H24!N"2O. — Hard  rhombic  prisms,  with  striated 

faces.     Melts  at  175°  C. 
CODEINA.     C18H21NO3. — Rectangular  octahedrons ;  or  (in  presence 

of  water)  trimetric. — 136,  138,  139. 

COLCHICIA.     C17H19]SrO5. — Colorless  prisms  or  needles;  yellow- 
ish-white powder;  glacial.— 135,  136,  138,  140. 
DAPHNIN.     C31H38O19. — Rectangular    prisms.       Odorous    above 

100°  C. ;  above  200°  C.,  Daphnetin.— 138,  141. 
DELPHINA. — Amorphous  ;  powder  white  with  yellow  tint.    Melts 

to  resinous  mass. — 136  (135,  e). 
DIGITALIN.     C10H18O4. — Difficult  to  crystallize.     A  Glucoside. — 

136  (135a)  (142). 
EMETIA.     C30H44N2O4. — Yellow-white    powder.     Melts    at    50° 

C.— 136,  138  (135,  e). 

ERGOTINA.     C50H52N2O3. — Red-brown  powder. — 136. 
HYDRASTIA. — Colorless,  shining,  four-sided  prisms.     Above  100° 

C.,  melts.— 136,  137,  140. 
HYOSCYAMIA.     C15H23K"O3. — Stellate    groups    of  silky   needles; 

amorphous  and  pasty.     Fusible. — 136. 
IQASURIA. — Colorless,  lustrous  prisms.     Fusible. — 136,  138,  140. 


126  NON-VOLATILE  ALKALOIDS. 

MORPHIA.      C17H19NO3(H2O).  —  Short,    transparent,    trimetric 

prisms.     Anhydrous  at  120°.— 136,  138,  141. 
NARCEINA.    C23H29WO9. — Colorless,  delicate  needles.    Fusible. — 

136,  137,  138,  139. 
NARCOTINA.     C22H23NO7. — Colorless,  rhombic  prisms.     Fusible. 

-136,  138,  139. 

OPIANIA.     C66H72N4O21. — Eight  rhombic  prisms. — 138,  139. 
.  PAPAVERINA.      C20H21NO4. — Colorless,    acicular    crystals. — 136, 

138. 

PAYTINA.     C21H24N2O. — Colorless  crystals. 
PHYSOSTIGMIA.       C15H2i;W3O2.  —  Amorphous,    brownish-yellow ; 

solutions,  red  to  blue. — 136,  140. 
PICROTOXIN.     C12H14O6. — Needles  ;  stellate  ;   laminae.     Eeduces 

cupric  hydrate.^137. 
PIPERIN.     C17H19NO3. — Colorless,  monoclinic  prisms.     Melts  at 

100°  C.— 136,  138. 
PSEUDOMORPHIA.      C17H19NO4. — Fine,    lustrous    crystals. — 136, 

138,  141. 
QUINIA.     C20H24N2O2. — Hydrate,    in    fine    needles.   -  Solutions, 

blue-fluorescent. — 136,  140. 

QUINIDIA.     C20H24N2O2. — Transparent,  monoclinic  prisms,  efflo- 
rescent.— 136,  140. 
EHCEADIA.     C21H21NO6. — Small,  white  prisms.     Melts  at  232°  C. 

— Purple-red  with  acids. 
SABADILLIA.     C20H26N2O5. — Cubic  crystals   (Needles?).     Eeacts 

with  sulph.  acid  like  Veratria  (136)  135,  e. 
SALICIN.     C13H18O7.  —  Tabular    or    scaly    crystals.  —  Melts    at 

120°  C.     A  Glucoside.— 136. 
SAPONIN.     C32H54O18. — Amorphous.     Aromatic  odor,  sweet  taste, 

burning  after-taste.     A  Glucoside. 
SOLANIA.     O43H69NO16. — Silky  needles ;  right,  four-sided  prisms. 

A  Glucoside.— 136,  138. 
STRYCHNIA.     C22H24N2O2. — Four-sided  prisms,  trimetric,  white. 

Fusible.— 136,  137. 
THEBAINA.     C]9H21NO3. — Thin,  square  tablets  of  silvery  lustre. 

Fusible.— 136,  138. 


SOL  UBILITIES.  1 27 

THEOBROMINA.     C7H8N4O2. — Microscopic,   trimetric  crystals,  in 

club-shaped  groups. — 136,  140. . 

VER ATRIA.     C32H52N2O8. — White  or  greenish- white  crystallized 
powder.     Warmed  with  HC1,  violet. — 136. 

133.  Solubilities  of  the  Alkaloids. — In  alcohol  they  are 
generally  freely  soluble,  the  following  being  the  only  important 
exceptions  and  notices  to  be  made  : 
CafFeina — in  30  parts  strong  alcohol. 
Morphia — in  30  parts  boiling  or  50  parts  cold  absolute ;  in  a 

somewhat  smaller  quantity  of  90  p.  c.  alcohol. 
Narceina — easily  in  hot,  in  950  parts  cold  85  p.  c.  alcohol. 
Narcotina — in  25  parts  boiling  or  100  parts  cold  85  p.  c.  alcohol. 
Opiania — slightly  in  hot,  scarcely  at  all  in  cold  alcohol. 
Pseudomorphia — nearly  insoluble. 
Solania — in  150  parts  hot  or  500  parts  cold  alcohol. 
Strychnia — difficultly   soluble  in  absolute,  soluble  in  115  parts 
of  95  p.  c.,  125  parts  of  90  p.  c.,   130  parts  cold  or  15 
parts  boiling  75  p.  c.,  250  parts  cold  or  25  parts  boiling 
50  p.  c.  alcohol. 
Theobromina — in  50  parts  hot  or  1500  cold  alcohol. 

The  solubilities  given  for  ether  in  the  table  refer  to  ether 
nearly  or  quite  free  from  alcohol. 

Benzole  (of  coal-tar),  as  used  below,  distils  at  60°  to  80°  C. 
(140°  to  176°  F.),  leaving  no  residue. 

Amylic  alcohol  dissolves  0.1568  part  of  Codeina,  0.0026  part 
of  Morphia,  0.0032  part  of  Narcotina,  0.0130  part  of  Papaverina, 
and  0.0167  part  of  Thebaina  (KUBLY). 

Ether  dissolves  from  acid  solutions — Colchicin,  Digitaiin, 
Picrotoxin — in  general  not  the  (other)  alkaloids. 

Petroleum  Naphtha,  as  used  below,  distils  at  from  40°  to 
60°  C.  (104°  to  140°  F.),  leaving  no  residue. 

Amylic  Alcohol  should  be  strictly  free  from  ethylic  alcohol. 

The  acid  used  with  chloroform,  benzole,  etc.,  is  sulphuric 
acid,  added  just  to  an  acid  reaction,  and  forming  sulphates  of  the 
alkaloids. 


SOLUBILITIES   OF  ALKALOIDS. 


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130  NON- VOLATILE  ALKALOIDS. 

134.  Separation  of  Alkaloids  from  (solid)  Albumenoid, 
Fatty,  and  Extractive  Matters. — (1)  The  alkaloids  are  dis- 
solved out,  as  salts  (tartrates,  sulphates,  or  acetates)  by  alcohol, 
at  a  gentle  heat ;  the  filtered  solution  is  evaporated  to  drjness, 
and  the  residue  dissolved  as  before,  etc.  For  removal  from 
Fats,  the  residue  is  dissolved  in  slightly  acidulated  water ;  the 
(filtered)  solution  evaporated  and  the  solution  repeated,  etc. — 
The  residue,  in  which  the  alkaloid  is  a  salt,  is  washed  with  ether, 
as  long  as  the  ether  removes  anything  (  OTTO'S  modification, 
1856).  The  washed  residue  is  treated  wTith  alkali,  in  presence 
of  ether,  which  dissolves  the  nascent  alkaloid.  The  residue  from 
the  ether  solution  is,  if  necessary,  purified  by  extraction  with 
alcohol,  or  acidulated  water,  or  each,  as  required  (STAS'  method. 
1851).  Also,  this  method  is  adapted  for  volatile  as  well  as  fixed 
alkaloids.  [The  extraction  with  ether  may  be  followed  by  use 
of  chloroform.] 

(2)  A  somewhat  more  simple  method  upon  the  same  princi- 
ple,  for   non-volatile   alkaloids   only,   with   use   of   chloroform 
instead   of   ether,   and  with   carbonization   by   sulphuric    acid 
(RODGERS  and  GIRDWOOD,  1856).     Designed,  by  its  authors,  for 
strychnia   only ;    but   applicable    for   all    alkaloids    soluble    in 
chloroform  and  not  decomposed  by  concentrated  sulphuric  acid 
at  100°  C. 

(3)  The  use  of  amylic  alcohol  (as  in  Otto's  and  Stas'  method) 
to  wash  the  acid  solution  of  alkaloids  clean  of  all  matters  soluble 
in  amylic  alcohol,  and,  after  saturating  with  alkali,  dissolving  the 
alkaloid  in  the  same  solvent.     Then,  the  amy lie-alcohol- solution 
of  alkaloids  is  washed  with  acidulated  water,  whereby  the  alka- 
loids are  removed  from  the  former  solvent  and  taken  up  by  the 
•water  as  salts.     This  is  repeated  -until  purification  is  complete. 
The  method  is  applicable  only  to  those  alkaloids  not  soluble  in 
amylic  alcohol  from  acid — see  Table,  133  (USLAR  and  ERDMANN, 
1861). 

(4)  The   use  of  animal   charcoal  to  withdraw  an   alkaloid 
(strychnia)  from  a  solvent ;  after  which  the  alkaloid  is  extracted 


METHODS   OF  SEPARATION.  131 

from  the  charcoal  by   a  more  effective  solvent.     (GRAHAM  and 
HOFMANN,  1853.) 

(5)  Dialysis  of  the  alkaloids,  as  salts,  from  colloid  matters 
(GRAHAM,  1862). 

(6)  Separation  of  Alkaloids  from  each  other,  as  well  as 
from    indeterminate    matters,    etc.      The    use     of    petroleum 
naphtha,  benzole,  chloroform,  and  amylic  alcohol,  each  first  in 
acid  and  then  in  alkaline  solutions — extracting  back  to  acidulated 
water  (as  in  method  of  Uslar  and  Erdmann)  when  necessary  to 
purify.     Division   of    the   alkaloids   into    about    eight    groups. 
(DRAGENDORFF,  1868.) 

(7)  Separation   of   alkaloids  from  each  other  and  from 
associated   Glucosides,   by   an   extension   of  the    method    last 
named. 

(8)  Separation  of  alkaloids  from  each  other  by  their  solu- 
bility in  alkali. 

(9)  Separation  of  pure  alkaloids  from  each  other  by  successive 
use  of  ether,  water,  and  chloroform.     (PRESCOTT.) 

(1)  Otto's  and  jStas*  Method. — An  aliquot  part  of  the  mate- 
rial is  finely  divided  if  solid,  or  concentrated  if  liquid,  and 
subjected  to  digestion,  at  about  60°  C.  (140°  F.),  with  a  double 
weight  of  90  per  cent,  alcohol,  with  addition  of  0.5  to  2.0  grams 
tartaric  acid  (or  oxalic  acid).  This  extraction  is  completed  by 
expression  and  digestion  with  another  portion  of  alcohol,  repeated 
two  or  three  times. — The  filtered  liquid  is  now  concentrated  to  a 
small  bulk — by  use  of  gentle  heat,  or  in  vacuum  [or  heat  with 
partial  vacuum  from  condensation  by  use  of  two  connected 
flasks*],  or  by  gentle  heat  in  a  stream  of  air  with  use  of  a  tubu- 
lated retort.  Fat  is  separated  by  filtration  through  a  wet  filter, 
and  the  filtrate  evaporated  nearly  or  quite  to  dryness,  in  vacuum 
or  over  sulphuric  acid. — Macerate  the  residue  in  absolute 
alcohol  (for  24  hours),  and  evaporate  the  filtrate  at  a  heat  not 
above  40°  C.  (104°  F.) — Moisten  the  residue  with  water,  and 

*  PRESCOTT  :  Chem.  News,  xx.,  p.  232  (1870,  Jan  ) 


132  ALKALOIDS. 

add  bicarbonate  of  sodium  or  potassium  as  long  as  there  is  effer- 
vescence.— Add  three  or  four  volumes  of  ether  (free  from  oil  of 
wine  and  not  heavier  than  0.725  s.  g.)  and  agitate.  Evaporate  a 
portion  of  the  clear  ether  upon  a  watch-glass ;  a  residue  in  oily 
streaks,  collecting  into  droplets,  having  a  pungent  odor  and  alka- 
line reaction,  gives  evidence  of  volatile  alkaloids. 

If  volatile  alkaloids  are  present,  the  material  is  farther  treated 
for  a  short  time  with  a  little  strong  potassa  solution,  and  then 
extracted  in  a  flask  or  large  test-tube  with  repeated  portions  of 
the  ether.  Acidulate  the  ether  solution  with  dilute  sulphuric 
acid,  stopper  tightly  and  agitate,  and  remove  the  ether  layer. 
(Ammonia,  anilin,  nicotia,  picolin,  as  sulphates,  are  not  soluble 
in  ether ;  conia  sulphate  is  slightly  soluble  in  ether.)  Evaporate 
the  ether,  at  ordinary  temperature,  and  test  for  Conia. — To  the 
acid  watery  residue  add  excess  of  potassa  or  soda,  and  extract 
with  ether  as  before.  Evaporate  the  ether  at  low  temperature, 
and  test  the  residue  for  volatile  alkaloids  (126). — For  non- volatile 
alkaloids,  unite  this  residue  with  any  fixed  residue  left  by  that  por- 
tion of  ether  taken  after  adding  bicarbonate,  and  treat  as  follows : 

For  non-volatile  alkaloids,  evaporate  the  (first)  ether-extract, 
dissolve  in  a  very  little  very  dilute  sulphuric  acid  (leaving  a 
decided  acid  reaction)  and  wash  with  ether  (absolute  or  nearly 
so)  as  long  as  anything  is  washed  away. — Now  add  fresh  ether, 
then  add  excess  of  concentrated  solution  of  carbonate  of  sodium 
or  potassium  and  extract  thoroughly  with  several  portions  of  the 
ether. — The  residue  from  the  ether  may  be  purified  by  extraction 
with  water  acidified  by  sulphuric  acid ;  then  the  concentrated 
aqueous  sulphate  is  treated  with  carbonate  of  potassium  in 
excess  and  extracted  with  absolute  alcohol. — At  each  evaporation 
the  appearance  of  crystals  is  watched.  Crystallization  from 
ethereal  solutions  is  greatly  promoted  by  adding  alcohol. 

(2)  Rodgers  and  Girdivood's  method. — The  material  is 
digested  with  dilute  hydrochloric  acid  at  a  moderate  heat  for 
about  two  hours ;  the  filtered  extract  evaporated  to  dryness  on 
the  water-bath ;  the  residue  extracted  with  water  and  filtered ; 


-£=~ 

8EPAEA  TION  B  Y  SOL  VENTS./f'  1 33 

if   -#"  *  .?*  • 
IV^n  *  E* 

and  the  filtrate  supersaturated  with  ammonia  and  then  extracted, 
in  a  flask,  with  chloroform. — The  solid  residue  from  the  chloro- 
form is  moistened  with  concentrated  sulphuric  acid  and  left  on 
the  water-bath  for  half  an  hour  or  longer  to  carbonize  foreign 
organic  matters.  When  cool,  it  is  then  extracted  with  water. — 
The  water  solution  is  saturated  with  ammonia  and  again  extracted 
with  chloroform.  If  the  residue  of  (a  portion  of)  the  chloroform 
blackens  on  warming  with  sulphuric  acid,  the  (whole)  residue  is 
again  treated  with  sulphuric  acid  on  the  water-bath,  extracted 
with  water,  and  the  aqueous  solution  with  ammonia  and 
chloroform. 

(3)  Method  of  Uslar  and  Erdmann. — Digest  the  material, 
brought  to  the  consistence  of  a  thin  paste  and  acidified  with 
hydrochloric  acid,  for  an  hour  or  two,  at  60°  to  80°  C.  (140°  to 
176°  F.),  and  strain  and  press  through  wet  linen,  washing  the  ' 
residue  with  water  acidified  with  hydrochloric  acid. — Evaporate 
the  united  solutions,  with  addition  of  clean  sand  and  of  ammonia 
in  excess,  and  triturate  to  a  powder.  Boil  the  residue,  repeat- 
edly, with  amylic  alcohol,  and  filter  the  extracts  hot  through 
paper  moistened  with  amylic  alcohol.  The  filtrate  is  usually 
yellowish,  and  holds  fatty  and  coloring  matters,  with  the  alka- 
loids, in  solution. — Transfer  the  filtrate  to  a  cylindrical  vessel, 
add  ten  or  twelve  times  its  volume  of  water  acidified  with 
hydrochloric  acid  and  nearly  boiling,  agitate  vigorously  and  set 
aside.  Remove  the  amylic-alcohol-layer  with  a  pipette.  (This 
should  be  nearly  or  quite  free  from  all  those  alkaloids  not  soluble 
in  amylic  alcohol  with  acid — the  only  ones  considered  in  this 
process.  See  Table,  133.  This  amylic  alcohol,  however,  may 
well  be  washed  with  one  portion  of  hot  acidulated  water.)  Wash 
the  water-acid  liquid  with  several  portions  of  amylic  alcohol. — 
Concentrate  the  water-acid  liquid,  add  ammonia  in  excess,  and 
repeat  the  extraction  with  hot  amylic  alcohol. — If  the  liquid  is 
colored,  or  if  the  residue  of  a  few  drops  is  blackened  by  a  drop 
of  sulphuric  acid,  again  extract  by  much  hot  acidulated  water, 
and  then  by  amylic  alcohol. 


134  ALKALOIDS. 

(4)  Method    with   Animal   Charcoal. — Shake    two    ounces 
animal  charcoal  in  half  a  gallon  of  the  aqueous,  neutral  or  feebly 
acid,  liquid  ;    let  the  mixture  stand  24  hours,  with  occasional 
shaking ;  filter ;  wash  the  charcoal  once  or  twice  with  water ; 
then  boil  half  an  hour  with  8  ounces  of  alcohol  of  80  to  90  per 
cent,  (condensing  and  returning  the  evaporated  alcohol.)     Filter 
and  evaporate  the  filtrate. — (Devised  by  its  authors  for  separa- 
tion of  strychnia  from  beer.) 

(5)  Dialysis. — The  aqueous  liquid  or  suspended  material  is 
acidified  with  hydrochloric  acid,  and  floated,  in  the  dialyzer,  over 
pure  water.    The  dialyzed  liquid  usually  contains  foreign  matter ; 
still  to  be  removed  by  some  other  process. 

(6)  Use    of  Naphtha,  Benzole,    Chloroform,   and  Amylic 
Alcohol,  each  in  Acid  and  in  Allcaline  Solutions.    Dragen- 
dorff's  Method. — The  finely-divided  material  is  extracted  several 
times   with  water   acidulated  with   sulphuric   acid,  digesting 
several  hours  at  a  temperature  of  40°  to  50°  C.     (If  it  is  desired 
to  examine  for  the  glucosides,  colchicin,  digitalin,  solanin,    the 
digestion   should   be   made  at  ordinary  temperatures.     Piperin 
may  be  in  part  undissolved.)     The  filtrate  is  treated  with  suffi- 
cient calcined  magnesia  to  leave  only  a  slight  acid  reaction,  and 
evaporated  over  a  water-bath  to  the  consistence  of  a  syrup.    This 
is  placed  in  a  flask,  treated  with  three  to  four  parts  of  70  to  80 
per  cent,  alcohol,  acidulated  with  sulphuric  acid,  and  digested 
with  frequent  agitation,  for  24  hours,  at  about  30°  C.     When 
cold,  the  liquid  is  filtered,  the  residue  being  washed  with  alcohol. 
The  filtrate  is  evaporated  to  remove  all  the  alcohol,  and  diluted 
with  water :  solution  A. 

Solution  A  is  digested  and  washed  in  a  flask  with  petroleum 
naphtha  (see  133),  at  about  35°  C.  Fats,  colors,  etc.,  and,  if 
present,  Piperin  are  dissolved :  solution  B. — The  watery-acid 
residue  from  solution  B  is  digested  and  washed  with  benzole  at 
about  45°  C.  If  a  small  portion  of  the  decanted  benzole  gives  a 
perceptible  residue,  the  whole  is  nearly  neutralized  with  magne- 
sia or  ammonia  (leaving  a  distinctly  acid  reaction)  and  then 


SEPARATION  BY  SOLVENTS.  135 

thoroughly  extracted  with  the  benzole  :  solution  C.  This  benzole 
solution  is  evaporated  in  glass  dishes,  for  examination  of  the 
residue.  It  may  contain  Caffeina,  Colchicin,  Cubebin,  Delpliina, 
Digitalin  (and  traces  of  Berberin,  Physostigmin,  and  Veratria). 
See  also  under  (7),  134. — The  watery-acid  residue  from  solution 
C  is  now  extracted  with  amylic  alcohol:  solution  D.  In  this 
solution  there  may  be  Berberin  (traces  in  C),  Narcotina  (perhaps 
only  in  part),  Physostigmia  (traces  in  C),  Theobromina,  Veratria 
(and  traces  of  Aconitina  and  Atropina) . — The  watery-acid  residue 
from  solution  D  is  now  extracted  with  chloroform :  forming 
solution  E.  This  may  contain  Papaverina,  Narcotina  (if  not 
wholly  in  D),  Thebaina,  and  perhaps  Veratria  left  from  the 
benzole  of  C. 

The  watery -acid  residue  of  E  is  now  made  slightly  alkaline 
by  ammonia,  and  extracted  at  about  35°  C.  with  petroleum 
naphtha. — If  a  little  portion  of  this  solution  gives  a  colored 
residue,  the  whole  of  it  is  thoroughly  washed  with  much  water 
acidulated  with  sulphuric  acid,  thus  transferring  the  alkaloids  to 
watery-acid  solution,  from  which  they  are  again  extracted  by 
making  alkaline  and  washing  with  petroleum  naphtha.  This, 
solution  F,  in  petroleum  naphtha,  may  contain  Brucia,  Coma, 
Emetia,  Nicotia,  Quinia,  Strychnia,  and  remaining  traces  of 
Veratria. — Two  of  these  are  volatile  and  liquid  alkaloids,  soluble 
from  the  residue  in  cold  water.  Evaporation  of  the  naphtha 
leaves  quinia  and  strychnia  crystalline ;  brucia,  emetia,  and  vera- 
tria,  amorphous.  Quinia,  emetia,  and  veratria  are  soluble  in 
absolute  ether ;  brucia  and  strychnia  insoluble. 

The  watery-alkaline  residue  of  F  is  now  extracted  several 
times  with  benzole,. at  about  40°  C.  If  a  portion  of  the  benzole 
leaves  a  colored  residue,  the  whole  is  extracted  with  acid-water 
and  again  taken  up  with  benzole  for  purification,  as  directed 
above  for  naphtha.  Solution  G  (in  benzole)  contains  Aconitia, 
Atropia,  Cinchonia,  Codeina,  Hyoseyamia,  Physostigmia, 
Quinidia. — These  alkaloids  are  all  soluble  in  ether,  except  cin- 
chonia.  If  the  residue  of  the  others  is  dissolved  ir. 


136  ALKALOIDS. 

acidulated  with  sulphuric  acid  and  then  supersaturated  with  am- 
monia, aconitia  and  quinidia  are  precipitated ;  while  atropia, 
codeina,  hyoscyamia,  and  physostigmia  are  (for  a  brief  time)  dis- 
solved. The  aconitia  and  quinidia  precipitate  being  dissolved  in 
hydrochloric  acid,  platinic  chloride  precipitates  only  the  quinidia. 

The  watery  alkaline  residue  of  G  is  now  acidulated  with 
sulphuric  acid  and  washed  at  about  55°  C.  with  amylic  alcohol ; 
then  made  alkaline  with  ammonia  and  extracted  with  ainylic 
alcohol  at  the  same  temperature.  If  the  residue  of  a  portion  of 
the  solvent  is  colored,  the  alkaloids  are  extracted  from  the  whole 
by  acidulated  water ;  and  again  extracted  by  amylic  alcohol  in 
presence  of  alkali  (as  directed  for  F  and  G).  Solution  H  (in 
amylic  alcohol)  contains  Morphia,  Narceina,  Solania. — Nar- 
ceina  is  dissolved  from  the  residue  by  warm  water. 

The  watery  alkaline  residue  of  H,  which  may  be  termed 
solution  I,  may  contain  Curarin,  and  traces  of  Berberina 
(Digitalin)  and  Narceina.  The  solution  (I)  evaporated  to  dry- 
ness,  with  pulverized  glass,  yields  its  alkaloids  to  alcohoL 

(7)  Separation  of  Alkaloids  and  Glucosides  from  each 
other.  Dragendorffs  scheme.  Use  of  the  solvents  and  opera- 
tions employed  in  (6). 

A.  Benzole  dissolves,  from  acid  (sulphuric)  aqueous  solutions 
— Caffeina,     Colchicin     (incompletely),    Colocynthin,    Cubebin, 
Delphina  (incompletely),  Digitalin,  Elaterin,  Narceina,  Piperin, 
Syringin — and  traces  of  physostigmia  and  veratria. 

B.  Benzole  dissolves,  from   alkaline   (ammoniacal),   aqueous 
solutions — Aconitia,  Atropia,  Brucia,  Cinchonia,  Codeina,  Coma, 
Delphina,  Emetia,  Hyoscyamia,  Narceina  (imperfectly),  Narco- 
tina,  Nicotia,  Papaverina,  Physostigmia,  Quinia,  Quinidia,  Strych- 
nia, Thebaina,  Veratria. 

c.  Benzole  fails  to  dissolve,  more  than  traces,  from  alkaline 
solutions — Morphia,  Salicin,  Solania,  Syringin,  Theobromina. 

D.  Benzole  does  not  dissolve,  either  from  acid  or  alkaline 
water  solutions — Curarin,  Picrotoxin,  Salicin,  Theobromina. 


SEPARATION  BY  SOLVENTS.  137 

E.  Benzole,  Petroleum  Naphtha,  Amylic  Alcohol,  and  Chlo- 
roform,  all  fail  to  dissolve,   from    acid  or  alkaline  solutions, 
Curarin. 

F.  Amylic   alcohol  dissolves,  from  acid    (sulphuric)    water 
solutions,  more  readily  when  warm — Aconitia  (very  sparingly), 
Berberina  (in  greater  part),  Brucia  (in  traces),  Caffeina,  Cantha- 
ridin,   Colchicin,   Cubebin,   Delphina,  Digitalin,  Narceina  (spar- 
ingly), Narcotina,  Picrotoxin,   Piperin,  Salicin,  Santonin,  Theo- 
bromina,  Veratria. 

G.  Petroleum  Naphtha  leaves  undissolved,  from  acid  or  alka- 
line solutions — Aconitia,  Berberina,  Caffeina,  Curarin,  Narceina, 
Salicin,  Syringin,  Physostigmia,  Theobromin. 

H.  Petroleum  Naphtha  dissolves  from  acid  (sulphuric)  watery 
solutions — Piperin,  Populin. 

i.  Petroleum  Naphtha  dissolves  from  alkaline  (ammoniacal) 
solutions — Brucia,  Conia,  Emetia,  Nicotia,  Papaverina,  Quinia, 
Strychnia,  Veratria,  and  traces  of  aconita,  berberina,  cinchonia, 
delphina,  narcotina. 

j.  Petroleum  Naphtha  does  not  dissolve,  from  alkaline  solu- 
tion— Caffeina,  Colchicin,  Delphina. 

K.  Chloroform  dissolves  from  the  add  (sulphuric)  water  solu- 
tion— Caffeina,  Colchicia,  Colocynthin,  Cubebin,  Delphina  (spar- 
ingly), Digitalin,  Narcotina,  Papaverina,  Piperin,  Picrotoxin, 
Santonin,  Thebaina,  Theobromina. 

L.  Chloroform  dissolves  from  the  alkaline  (ammoniaeal) 
water  solution — Aconitia,  Atropia,  Berberina  (sparingly),  Brucia, 
Caffeina,  Cinchonia,  Codeina,  Colchicin,  Conia,  Cubebin,  Del- 
phina, Digitalin,  Emetia,  Hyoscyamia,  Morphia  (sparingly), 
Narcotina,  Narceina  (sparingly),  Nicotia,  Papaverina,  Piperin, 
Quinia,  Strychnia,  Thebaina,  Theobromina,  Veratria. 

(8)  Separation  of  certain  alkaloids  from  each  other  by 
solubility  in  alkali. 

A.  Solutions  of  Fixed  Alkalies  precipitate,  and  by  excess 
redissolve,  in  dilute  solution — Atropia,  Berberina,  Codeina, 


138  ALKALOIDS. 

Conia,  Hyoscyamia  (partly),  Morphia,  Nicotia,  Solania — Colchi- 
cin  being  decomposed. 

Most  of  the  other  well-known  alkaloids  are  left  in  precipitate 
by  excess  of  fixed  alkali. 

B.  Of  those  not  redissolved  by  fixed  alkalies,  Ammonia  in 
strong  excess  dissolves  from  precipitate — Aconitia,  Colchicin, 
Hyoscyamia,  Physostigmia,  Strychnia. 

(9)  Separation  by  successive  use  of  Ether,  Water  (and 
Chloroform). — The  alkaloids  are  previously  obtained  pure,  as 
bases,  and  in  the  solid  state  finely  divided.  The  ether  used  is 
absolute,  applied  in  proportion  of  40  to  60  parts  to  one  of  the 
solid,  with  agitation  and  digestion  in  a  stoppered  flask.  The 
water  is  applied  hot,  and  in  proportion  of  fully  100  parts  to  one 
of  solid.  The  chloroform  should  be  nearly  or  quite  free  from 
alcohol,  and  20  to  40  parts  used.  Alkaloids  which  are  appre- 
ciably divided  by  the  solvents  have  their  names  placed  in 
parentheses. 

ALKALOIDS. 

Treat  with  Ether  and  filter. 

Evaporate  Filtrate  (a)  to  resi-  Residue  (b). 

due  (a). 
Treat  residue  (a)  with  water.  Treat  Residue  (b)  with  water. 

Flit.   (A)  Res.  (B).  Filtrate  (c).  Residue  (D) 

Eoap.to  res.  Evap.  to  residue  (c). 

(A).  Treat  (c)  with  chloroform.    Treat  (D)  with  chloroform. 

Flit.    (C).          Res.  (D).     "     Flit.    (E)      "~ResT  (F).    " 
Evap.  to  resid.  Evap.  to  res. 

(C)  (E). 

(A)  (B)  (C)  (D)  (E)  (F) 

Sol.  in  Ether.    Sol.  in  Ether.    Ins.in  Ethtr.    I  us.  in  Ether.    Ins.  in  Ether.  Ins.  in  Ether. 
"    Water.       Ins.inWater.    Sol.  i~i Water,    Sol.  in  Water.      "       Water.     "       Water. 
"       Chl'm.    Ins.  in  Chfm.   Sol.  in  ChVm.     "        Ch?m. 

Aconitia.  Delphlna.          (Berberina).     (Berberina).     Cinchonia.        (Digitalin.) 

Atropla.  (Hydrastia).     Brucia.  Ergotina.          (Digitalin).       Pseudoraor- 

Codeina.  (Lobelina).       Caffeina.  (Narcelna).       (Hydrastia).        phia. 

Colchicin.         Narcotina.        Emetia.  (Salicin).          Morphia.  Solania. 

Conia.  Paytina.  (Igasurla).        (Saponin).        (Narcelna).      (Theobromlna). 

Hyoscyamia.     Physostigmia.  (Narceina).  Papaverina. 

(Igasuria).        Piperin.  (Picrotoxin).  Rhreadia. 

Nicotia.  Qulnla.  (Salicin).  Strychnia. 

(Picrotoxin).    Quinidia.  (Saponin).  (Theobromlna) 

Thebalna. 
Veratria. 


GENERAL  REAGENTS.  139 

135.  Detection  and  separation  of  alkaloids  as  a  class. 

The  material  is  obtained  in  solution,  and  free  from  albumenoid, 
gelatinoid,  gummy,  coloring,  and  "  extractive "  substances. 
Also,  the  presence  of  inorganic  acids,  bases,  or  salts  which  react 
with  the  several  reagents,  must  be  avoided.  Then,  the  alkaloids 
are  precipitated — by  potassio  mercuric  iodide  (also  a  means  of 
volumetric  determination)  (a) ;  by  phosphomolybdic  acid  (per- 
mitting a  division  of  alkaloids  by  subsequent  use  of  ammonia) 
(b) ;  by  metatungstic  acid  (c)  ;  by  potassio  cadmic  iodide  (d)  ; 
by  picric  acid  (with  distinguishing  exceptions)  (e) ;  by  tannic 
acid  (with  exceptions  and  peculiarities)  (/)  ;  by  solution  of 
iodine  with  iodide  (^7). 

a.  The  potassio  mercuric  iodide  reagent  is  prepared  by  add- 
ing to  solution  of  mercuric  chloride  enough  potassic  iodide  to 
dissolve  the  precipitate  first  formed.  It  gives  precipitates  in 
even  dilute  solutions  of  nearly  all  alkaloids  except  Caffeina, 
Colchicin,  Digitalin,  Theobromina  /  the  precipitates  being 
mostly  yellowish-white.  For  the  reactions  with  the  Volatile 
Alkaloids  and  Ammonia,  see  131,  The  precipitates  are  insoluble 
in  acids  (distinction  from  ammonia),  or  in  dilute  alkalies,  but 
soluble  in  alcohol  and  (in  many  cases)  in  ether — also,  in  many 
cases,  soluble  in  excess  of  the  precipitant. — For  the  extraction  of 
the  alkaloid  from  the  precipitate,  triturate  the  latter  with  stan- 
nous  chloride  and  enough  potassa  solution  to  give  a  strong  alka- 
line reaction,  then  exhaust  with  ether  or  chloroform,  or,  if  the 
alkaloid  is  not  soluble  in  these,  add  potassic  carbonate  instead  of 
potassa  and  extract  with  strong  alcohol. 

For  the  volumetric  determination  by  potassio  mercuric 
iodide  (MAYER),  the  reagent  is  prepared  with  13.55  grams  mer- 
curic chloride,  5  grams  potassic  iodide,  and  water  to  one  litre. 
Of  this  standard  solution,  1  c.c.  precipitates,  of  each  alkaloid,  the 
quantities  stated  below : 


Aconitia,      0.0268  gram. 
Atropia,       0.0145     " 
Brucia,         0.0233     " 


Cinchonia,   0.0102  gram. 
Conia,  0.0042     " 

Morphia,      0.0200     " 


140 


ALKALOIDS. 


Narcotina,   0.0213  gram. 
Mcotia,         0.0040      " 
Quinia,          0.0108      " 


Quinidia,     0.0130  gram. 
Strychnia,   0.0167      " 
Veratria,      0.0269     " 


The  volumetric  determination  is  somewhat  unsatisfactory, 
by  reason  of  the  slowness  with  which  the  precipitate  subsides. 
The  alkaloid  solution  is  slightly  acidulated  with  sulphuric  or 
hydrochloric  acid  ;  after  each  addition  of  the  reagent  the  mixture 
is  strongly  shaken  and  left  to  subside  ;  then  a  drop  of  the  clear 
liquid  is  placed  on  a  blue  or  black  glass  plate,  and  treated  with 
a  drop  of  the  reagent — to  learn  whether  further  addition  is 
necessary. 

1).  Phosphouiolybdic  acid  solution* — SONNENSCHEIN'S  Re- 
agent— gives  amorphous  and  mostly  yellow  precipitates  with  the 
alkaloids,  as  below.  The  alkaloid  solution  should  be  neutral  or 
slightly  acid,  as  alkalies  dissolve  the  precipitate  in  most  cases. 
The  reaction  with  ammonia  should  be  noted  ten  minutes  after 
its  addition. 


PRECIPITATE. 

WITH  AMMONIA.             ON  BOILING. 

Aconitia. 

Yellow. 

Blue  solution.                    Colorless. 

Anilin. 
Atropia. 
Berberina. 

Blue,  then  yellow. 
Yellow. 

<( 

tt                it 

Blue  to  colorless  sol.        Colorless. 
Blue  solution. 

Brucia. 
Caffeina. 

Orange. 
Yellow. 

Yellow-green  solution.    Brown. 
Colorless  solution. 

Cinchonia. 
Codeina. 
Colchicin. 

Conia. 

Whitish-yellow. 
Brownish-yellow. 
Yellow. 

Yellow-white. 

u               « 
Green  solution.                 Orange-red. 
Bluish  solution,  in  #  hr. 
greenish. 
Bluish  or  greenish  pre.  Colorless. 

*  The  yellow  precipitate  formed  on  mixing  acid  solutions  of  molybdate 
of  ammonium  and  phosphate  of  sodium — the  phosphomolybdate  of  ammo- 
nium— is  well  washed,  suspended  in  water,  and  heated  with  carbonate  of 
sodium  until  completely  dissolved.  The  solution  Is  evaporated  to  dryness, 
and  the  residue  gently  ignited  till  all  ammonia  is  expelled  (sodium  being 
substituted  for  ammonium).  If  blackening  occurs,  from  reduction  of 
molybdenum,  the  residue  is  moistened  with  nitric  acid  and  heated  again. 
It  is  then  dissolved  with  water  and  nitric  acid  to  strong  acidulation  ;  the 
solution  being  made  ten  parts  to  one  of  residue.  It  must  be  preserved  from 
contact  with  vapor  of  ammonia. 


GENERAL    REAGENTS. 


141 


PRECIPITATE.  WITH  AMMONIA. 

Delphina.  Gray-yellow. 

Digitalin.  Yellow,  on  warm-  Blue  solution, 

ing  dissolves  gr'n. 

Emetia.  Yellowish. 

Ergotina.  (A  precipitate.) 

Morphia.  Yellowish.  Dark  blue  sol.,  in  %  hr. 

a  blue  residue  falls. 

Narceina.  Brown-yellow,  be- 

coming resinous. 


ON  BOILING. 

Green,  then 
colorless. 


Narcotina. 

Brown-yellow. 

Nicotia. 

YeUow. 

Blue  solution. 

Papaverina. 

In   dilute   sol., 

no 

precipitate. 

Physostigmia. 

Yellow. 

Blue  precipitate. 

Piperin. 

Brown-yellow. 

Colorless  solution. 

(Piperidin. 

Clear  yellow. 

Blue  solution.) 

Quinia. 

Yellow-white. 

Whitish  precipitate. 

Quinidia. 

tt 

«                      (C 

Solaiiia. 

Yellow. 

Colorless  solution. 

Strychnia. 

Yellow-white. 

«             n 

Theobromina. 

u 

Veratria. 

YeUow. 

Colorless  precipitate. 

c.  Metatungstic  acid  precipitates  alkaloids  from  very  dilute 
solutions  (SCHEIBLER).    The  reagent  may  be  prepared  by  adding 
phosphoric  acid  to  a  solution  of  ordinary  tungstate  of  sodium  as 
long  as  a  precipitate  is  formed  and  redissolved.     The  precipitates 
are  white  and  flocculent.     This  test  is  more  delicate  than  that 
with   phosphomolybdic   acid.     Scheibler   states  that   a   distinct 
turbidity   is   produced  in  a  solution  of  one  part  of  quinia   or 
strychnia  in  200,000  of  water. 

d.  Fotassio  cadmic  iodide  solution  (prepared  like  potassio 
mercuric  iodide*)  (MARME'S  test)  gives  gray-yellow  to  yellow 
precipitates  with  the  alkaloids.     The  solution  of  alkaloid  should 
be  feebly  acidulated  with  sulphuric  acid.     The  precipitates  are 
easily  soluble  in  alcohol,  insoluble  in  ether,  soluble  in  excess  of 
the  reagent,  and  decompose  on  long  standing.     Precipitates  are 
obtained  with 


*  Dissolve  20  parts  iodide  of  cadmium  and  40  parts  iodide  of  potassium 
in  120  parts  of  water. 


142  ALKALOIDS. 

Aconitia,  Delphina,  Piperin, 

Atropia,  Emetia,  Piperidin, 

Berberina,  Hyoscyamia,  Quinia, 

Brucia,  Morphia,  Quinidia, 

Cinchonia,  Narceina,  Sanguinarin  (red), 

Codeina,  Narcotina,  Strychnia, 

Conia,  Nicotia,  Thebaina, 

Curarin,  Papaverina,  Veratria. 

Cytisin,  Physostigmia, 

No  precipitates  are  obtained  (in  dilute  solutions)  from  Col 
chicin,  Solania,  Theobromina,  or  from  other  known  glucosides 
and  neutral  substances. — The  alkaloids  are  obtained  from  their 
precipitates  by  adding  an  excess  of  carbonate  of  sodium,  drying, 
and  extracting  with  ether,  chloroform,  or  benzole,  according  to 
the  solubility  of  the  alkaloids  sought. 

e.  Picric  or  Trinitrophenic  acid  precipitates  from  water 
solutions  the  larger  number  of  the  alkaloids,  especially  as  sul- 
phates. Presence  of  free  sulphuric  acid  generally  promotes 
these  precipitations  and  enables  them  to  be  formed  in  more 
dilute  solutions.  On  the  contrary,  they  are  dissolved  by 
hydrochloric  acid. 

No  precipitates  are  formed  by  picric  acid,  in  acid  sulphate 
solutions  of  Anilin,  Caffeina,  Morphia,  Pseudomorphia,  Solania 
(unless  by  long  standing),  Theobromina,  and  the  Glucosides. — 
Aconitia  and  Atropia  are  not  precipitated  except  in  concentrated 
solutions. — Atropia  and  Morphia  are,  however,  precipitated  in 
neutral  solutions. — Sabadillia  in  150  parts  of  water  is  not 
precipitated. 

Full  precipitates  are  obtained  from  the  strongly  acid  sul- 
phates of  Berberina,  Colchicin,  Delphina,  Emetia, .  the  Cinchona 
alkaloids,  the  Opium  alkaloids  with  the  exceptions  above  given, 
the  Strychnos  alkaloids,  Veratria,  etc. 

The  following  results  are  obtained  by  treating  about  a  grain 
of  a  water  solution  of  (neutral)  salt  of  the  alkaloids  with  an 
alcoholic  solution  of  picric  acid  (WORMLEY)  : 


GENERAL   REAGENTS.  143 

Least  quantity  of  alkaloid 
Precipitate.  showing  precipitate. 

Aconitia.  Yellow,  amorphous.  WOTTO  gram- 

Atropia.  Yellow,  crystalline. 

Brucia.  Yellow. 

Codeina.  Yellow,  amorphous. 

Conia.  Yellow,  crystalline.  nro~o 

Morphia.  Yellow,  amorphous. 

Narceina.  "  " 

Narcotina.  "  " 

Nicotia.  «  «  -^^       « 

Solania.  «  "  T-JW 

Strychnia.  Yellow,  crystalline.  2  g *  0  0       " 

Veratria.  Yellow,  amorphous.  ToVo"        " 

The  alkaloids  may  be  extracted  from  their  picrates  by  addi- 
tion of  an  alkali  and  chloroform,  benzole,  or  other  suitable 
solvent.  (Alcohol  does  not  dissolve  potassic  picrate ;  but  it  takes 
up  the  excess  of  potassa.) 

f.  Tannic  acid — in  solution  with  8  parts  of  water  and  1  part 
of  alcohol — gives  whitish,  grayish-white,  or  yellowish  precipi- 
tates with  nearly  all  the  alkaloids.  In  the  larger  number  of 
instances  these  precipitates  are  easily  soluble  in  acids,  frequently 
dissolving  in  excess  of  the  tannic  acid ;  on  the  contrary,  some  of 
the  alkaloids  are  precipitated  by  tannic  acid  only  in  strong  acid 
solutions.  Ammonia  dissolves  the  tannates  of  the  alkaloids. 

No  precipitates  are  obtained  with  Piperin,  Salicin,  or 
Saponin. 

Dilute  acetic  acid  dissolves  the  precipitates  of  tannates  of 
Aconitia,  Brucia,  Caffeina,  Colchicin,  Morphia,  Physostigmia, 
Quinia  (if  the  acid  is  not  very  dilute),  Solania,  Veratria. 

Cold  dilute  hydrochloric  acid  does  not  dissolve  the  precipi- 
tates of  tannates  of  Aconitia,  Berberina,  Brucia  (slightly  dis- 
solves), Caffeina,  Cinchonia,  Colchicin  (dissolves  slightly),  Del- 
phina,  Digitalin,  Narcotina,  Papaverina,  Thebaina,  Soiania, 
Strychnia  (dissolves  sparingly),  Veratria. 


144  ALKALOIDS. 

Cold  dilute  sulphuric  acid  does  not  dissolve  the  precipitates 
of  tannates  of  Aconitia,  Physostigmia,  Quinia,  Solania,  Veratria. 

Precipitates  are  formed  in  neutral  solutions  (not  very  dilute), 
but  not  in  slightly  acid  solutions,  yet  completely  formed  in  solu- 
tions strongly  acidulated  with  sulphuric  acid,  by  Aconitia, 
Physostigmia,  Solania,  Veratria. 

Concerning  the  reactions  of  the  Volatile  Alkaloids  with  tannic 
acid,  see  131. 

Alkaloids  are  separated  from  their  tannates  by  mixing  the 
moist  precipitate  with  oxide  or  carbonate  of  lead,  drying  the 
mixture,  and  extracting  with  alcohol,  ether,  or  chloroform. 

g.  Water  solution  of  iodine  in  iodide  of  potassium  precipi- 
tates the  alkaloids  in  general.  The  solution  is  made  of  3  parts 
of  iodine,  5  of  iodide,  and  50  of  water.  (WORMLEY  :  1  of 
iodine,  3  of  iodide,  and  60  of  .water.) — The  precipitates  are 
yellow,  orange-yellow,  reddish-brown,  and  brown. — No  precipi- 
tates are  obtained  with  (Ammonia),  Caffeina  (in  neutral  solution), 
Digitalin  (or  but  slight  turbidness),  Solania,  Theobromina. — 
Yellow  precipitates  are  given  by  Atropia  (sparingly  saturated), 
Hyoscyamia,  Physostigmia,  and  Trimethy lamia  (orange-yellow). 
Red-brown  precipitates  are  obtained  with  Aconitia,  Codeina, 
Conia,  Lobelina,  Morphia,  Narceina,  Narcotina,  Nicotia,  Quinia, 
Strychnia,  and  Veratria. 

136.  Concentrated  sulphuric  acid  gives  characteristic  reac- 
tions with  some  of  the  alkaloids ;  and  a  greater  number  of  good 
indications  are  given  by  FROZHDE'S  reagent,  which  consists  of  0.01 
gram  molybdate  of  sodium  dissolved  in  10  c.c.  of  concentrated 
sulphuric  acid  (and  so  prepared  freshly  each  time  it  is  required). 
For  these  tests  the  alkaloids  must  be  almost  absolutely  free 
from  impurities  not  alkaloids.  One  or  two  miligrams  of  the 
alkaloid  are  dropped  upon  15  drops  of  the  acid. 

CONG.    SULPHURIC    ACID.  FRCEHDE'S  REAGENT. 

Aconitia.  Slight  yellow  to  yel.-br'n.  Yellow-brown  ;  colorless. 

Amygdalin.  Light  violet-red. 

Atropia.  Colorless  solution.  Colorless. 


REACTIONS    WITH  SULPHURIC  ACID. 


145 


CONG.    SULPHURIC    ACID.          FRCEHDE'S  REAGENT. 


Berberina. 

Dark  olive-green. 

Greenish-brown  to  brown. 

Brucia. 

Pale  rose. 

Red  ;  yellow. 

Caffeina. 

Colorless. 

Colorless. 

Cinchonia. 

Colorless. 

Colorless. 

Codeina. 

Colorless. 

Green  ;  blue  ;  yellowish. 

Colchicin. 

Yellow. 

YeUow. 

Colocynthin. 

Cherry-red  (slowly). 

Colombin. 

Orange,  turning  red. 

Conia. 

Colorless  (pale  reddish  ?). 

Pale  yellow. 

Cubebin. 

Bright  red,  then  crimson. 

Curarin. 

Lasting  blue. 

Delphina. 

Brownish. 

Red-brown. 

Digitalin. 

Brown  to  red-brown. 

Orange  ;  cherry-red  ;br'wn. 

Elaterin. 

Red. 

YeUow. 

Emetia. 

Brownish. 

Ergotina. 

Red-brown. 

Hesperidin. 

Yellow-red. 

Hydrastia. 

Colorless  ;    after    heating, 

purple. 

Hyoscyamia. 

Brownish. 

Igasuria. 

Rose-color  :    yellowish  ; 

greenish. 

Limonin. 

Yellow-red. 

Meconin  (Opianyl). 

(With  heat,  blue  to  purple). 

Morphia. 

Colorless. 

Violet  ;     green  -  yellow  ; 

violet. 

Narceina. 

Brown  to  yellow. 

Yellow-brown  ;  yellowish  ; 

colorless. 

Narcotina. 

Yel.  ;  purple  after  warm'g. 

Green  ;  yellow  ;  reddish. 

Nicotia. 

jColorless. 

Yellowish  ;  reddish. 

Ononin. 

Red. 

Papaverina. 

Violet  ;  blue. 

Violet  ;  blue  ;  yel'w  ;  color- 
less. 

Phloridzin. 

(Slowly)  blue. 

Physostigmia. 

Yellow  ;  olive-green. 

Piperin. 

Pale  yellow  ;  brown. 

Yellow  ;  brown. 

Populin. 

Red. 

Violet. 

Pseudomorphia. 

Olive-green. 

Quinia. 

Colorless. 

Colorless  ;  greenish. 

Quinidia. 

Nearly  colorless. 

Colorless  ;  greenish. 

Salicin. 

Bright  red. 

Violet  ;  cherry-red. 

Sarsaparillin. 

Deep  red,  then  violet,  then 

yellow. 

Senagin. 

Yellow-red. 

146  ALKALOIDS. 

CONC.    SULPHURIC  ACID.  FRCEHDE'S  REAGENT. 

Smilacin.  Yellow-red. 

Solania.  Reddish-yellow.  Cherry-red  ;     red-brown ; 

yellow. 

Strychnia.  Colorless.  Colorless. 

Syringin.  Blood-red,  then  violet-red. 

Tannicacid.  Purple-red. 

Thebaina.  Blood-red  ;  yellow-brown.    Orange. 

Theobromina.  Colorless.  Colorless. 

Veratria.  Slowly  to  crimson  red.         Yellow  ;  cherry-red. 

137.  Sulphuric   acid  and   bichromate  of  potassium:    the 

solid  alkaloid  being  dissolved  in  the  acid  and  a  very  minute 
fragment  of  the  bichromate  being  brought  into  contact  with  the 
liquid. 

With  Strychnia,  a  brilliant  play  of  changing  colors,  blue 
turning  soon  to  violet  and  then  red-violet,  then  slowly  fading 
— (delicate  and  distinctive).  With  Brucia,  an  orange  or  brown- 
ish-orange color.  With  Narceina,  a  dirty-red  mixture.  With 
Hydrastia,  a  brick-red  to  carmine-red  color;  with  Picrotoxin, 
red- brown.  With  anilin,  a  yellowish  to  greenish  tint  first  ap- 
pears, slowly  passing  into  blue,  which  after  half  an  hour  or 
longer  becomes  nearly  or  quite  black.  With  Curarin,  a  play  of 
colors  similar  to  strychnia  (compare  136).  With  aconitia, 
atropia,  codeina,  conia,  morphia,  narcotina,  nicotia,  solania, 
veratria,  and  many  other  alkaloids, — there  is  only  the  slowly 
formed  greenish  color  of  chromic  oxide. 

This,  the  strychnia  test,  may  be  made  with  substitution  of 
other  oxidizing  agents  for  the  bichromate,  the  crystallized  per- 
manganate of  potassium  perhaps  giving  the  best  results.  SON- 
NENSCHEIN  advocates  the  use  of  ceroso-ceric  oxide. 

138.  Concentrated  Nitric  acid,  of  spec.  grav.  1.42,  gives  a 
red  or  reddish-yellow  color  with  the  greater  number  of  the  alka- 
loids. 

Brucia,  in  the  solid  state,  is  dissolved  by  nitric  acid  with 
intense  blood-red  color — solutions  of  the  alkaloid  giving  the 
same  with  less  intensity  or  a  reddish-yellow  color.  On  warm* 
ing,  or  standing,  the  color  changes  to  yellow :  if  now  a  drop  of 


REACTIONS    WITH  NITRIC  ACID.  147 

solution  of  stannous  chloride  is  added,  a  purple  color  appears. 
The  purple  is  discharged  by  either  nitric  acid  or  excess  of  stan- 
nous salt.  Igasuria  gives  nearly  the  same  reaction,  both  with 
nitric  acid  and  stannous  chloride ;  the  violet  to  purple  color  with 
the  last-named  reagent  being  characteristic  of  brucia  and  igasuria. 

Morphia  in  somewhat  concentrated  solutions  is  colored  yel- 
low to  orange-red — the  color  is  either  not  changed  or  is  altered 
toward  the  yellow  by  stannous  chloride  (distinction  from  brucia). 
— Codeina,  Narceina,  and  Papaverina  are  colored  red  to 
orange-yellow  by  nitric  acid ;  and  Narcotina,  Pseudomorphia, 
Opiania,  Thebaina,  and  Rhceadia,  yellow,  Emetia  is  changed 
to  a  yellow,  resinous  mass,  with  partial  decomposition. 

Colcliicin  is  colored  violet  by  nitric  acid :  the  most  concen- 
trated nitric  acid,  containing  nitrous  acid,  forming  an  intense 
blue-violet  color.  The  color  changes  to  brown,  and  finally  to 
yellow — these  tints  being  more  distinct  in  proportion  as  the 
violet  is  deeper.  If  the  chloroform  solution  of  colchicin  is 
treated  with  concentrated  nitric  acid,  a  violet-red  color  is  formed 
and  taken  up  by  the  chloroform  layer. — Curarin  is  colored 
purple  by  nitric  acid. 

Nitric  acid  produces  no  color  with  Atropia  (brown  tint,  fad- 
ing), Caffeina,  Cinchonia,  Conia  (sometimes  yellowish),  Quinia, 
Quinidia,  Solania  (becoming  faint  rose-red  with  bluish  rim), 
Theobromina. 

Berberina  is  colored  brown  by  nitric  acid. 

Daphnin  is  colored  red. 

Piperin  becomes  greenish-yellow,  orange,  then  red,  and 
resinous. 

139.  Concentrated   sulphuric   acid  followed  by  nitrate  of 
potassium   (solid),  with  Narcotina  gives  a  deep  blood-red  color 
(delicate  and  distinguishing).     The  color  is  discharged  by  much 
excess  of  nitric  acid. — In  the  same  test,  Brucia  gives  an  orange- 
red,   and    Opiania   a   scarlet-orange    color.     Codeina   becomes 
first  greenish,  then  reddish.     Narceina  turns  reddish-brown. 

140.  Chlorine  water  followed  by  ammonia. — Quinia  (or 


148  ALKALOIDS. 

Quinidia)  treated  first  with  fresh  chlorine  water  and  then  with 
ammonia,  gives  a  green  flocculent  precipitate  which  by  excess  of 
ammonia  dissolves  to  an  emerald-green  solution  (characteristic). 
On  neutralization  with  an  acid,  the  color  changes  to  light  blue, 
which  becomes  violet  or  red  on  supersaturation  with  acid,  re- 
turning to  green  with  addition  of  excess  of  ammonia.  Addition 
of  solution  of  red  ferricyanide  of  potassium  to  the  ammoniacal 
green  solution  produces  a  red  color  (with  Quinidia  a  bulky 
precipitate).  A  better  result  is  obtained  by  adding  the  ferricy- 
anide after  the  chlorine  and  before  the  ammonia.  The  impure 
chlorine  obtained  by  addition  of  hydrochloric  acid  to  chlorate 
of  potassium  serves  the  purpose  of  this  test. 

Colchicin,  when  treated  with  chlorine  and  ammonia,  gives  an 
orange  solution. — Caffeina  and  Theobromina,  treated  with 
chlorine  water  (or  nitric  acid),  then  evaporated  to  dry  ness,  on 
addition  of  ammonia  give  a  purple-red  color.  CJilorine,  alone, 
with  Brucia  and  writh  Igasuria  gives  a  light  red  color;  with 
Hydrastia,)  blue  fluorescence.  Pliysostigmia,  with  solution  of 
chlorinated  lime,  gives  an  intense  red  color,  turning  nearly 
black  by  farther  addition. 

141.  Solution  of  Ferric  chloride  (dilute)  colors  solid  Mor- 
phia, and   Pseudomorpliia  blue.     Also  Daphnin  blue  in  the 
cold,  turning  yellow  when  warmed. 

Morphia  separates  iodine  from  iodic  acid. 

142.  Platinic    chloride    solution    precipitates    the    greater 
number  of  the  alkaloids,  even  dilute  solutions  (those  in  2,000  or 
3,000  parts  of  water) — the  precipitates  being   yellow,  whitish- 

" yellow  or  grayish-yellow,  and  some  of  them  being  soluble  in 
cold  hydrochloric  acid. — Anilin,  Digitalin,  Physostigmia,  and 
Solania,  are  not  precipitated ;  and  Aconitia,  Atropia,  Codeina, 
Hyoscyamia,  Narcotia,  Nicotia,  Sabadillia,  and  Veratria  only 
from  concentrated  solutions. — The  alkaloids  next  named  give 
precipitates  ;  each  precipitate,  after  ignition,  leaving  a  weight 
of  pure  platinum  bearing  a  fixed  ratio  to  the  weight  of  the  alka- 
loid— in  accordance  with  the  formula  given. 


DETERMINATION   BY  PLATINIC    CHLORIDE. 


149 


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150 


ALKALOIDS. 


143.  Auric  chloride  gives  precipitates  in  water  solutions  of 
salts  of  the  greater  number  of  the  alkaloids,  as  follows.  Many 
of  the  precipitates  are  soluble  in  alcohol.  Some  of  them,  on 
standing,  separate  the  gold.  The  dried  and  ignited  precipitates 
yield  fixed  quantities  of  metallic  gold,  according  to  the  formulae 
and  percentages  given : 


P.  C.  Au 
Aconitia,  C30H47NO7.HCl.AuCl3 

Atropia,  C17H23NO3.H  Cl.AuCl3 
Berberina,  C20H17NO4.H  Cl.AuCl,    . 

Brucia,    ...... 

Caffeina,  C8H10N4OrH  Cl.AuCl3 
Cinchonia,        ..... 

Cinchonidia,  C20H24N2O(H  Cl)2AuCl3 
Codeina,  no  precipitate,   . 

Colchicin, 

Delphina,         ..... 
Digitalin,         .         .         .         . 

Emetia, 

Hyoscyamia,  ..... 

Morphia,          ..... 


Narceina, 
Papaverina,     , 
Physostigrnia, 

Quinia,    . 


in  pre.     Color,  etc. ,  of  the  pre. 

22.1     Light  yel.,  reduced 

after  a  time. 
31.3     Light  yel. 

29.1  Dark  yel.,  insol.  in 

HC1. 

(Like    Strychnia). 
37.0     Lem.-yel.,  cryst'e. 
Yel.,  (like  Quinia). 
Yel.,  amorphous, 
(in  concentrated  solutions 
a  brown  precipitate). 
Slowly,  yel.  flocks; 
becom'g  reduced. 
Light  yel. 
Slowly,    a   yellow 

cryst'e  precip. 
129.7     Light  yel.,  amorp. 

31.2  Yel.-white. 
Light  yel.,  dark'g, 

insoluble  in  cold 

HC1. 

Yel.,  becom.  red'd. 
Dark  yel. 
Red'ish-blue  color, 

with  reduction. 
Light  yel.,  amorp. 


ABSINTHIN. 


151 


P.  C.  Au  in  pre.     Color,  etc. ,  of  the  pre. 

Quinidia,  CMH24NaO2(HCl)2(AuCl3)2     39.1     (Like  Quinia)  dry 

first  in  vacuo, 
then  at  100°  C. ; 
melts  at  115°  C., 
or  in  boil,  water. 


Solania,  no  precipitate. 
Strychnia,  C21H22N2O2.H  Cl.AuCl3 


Thebaina,         .... 
Theobromina, 

Veratria,  C32H52N2O8.H  Cl.AuCl3 


29.2     Yel.,  amor.,  sol.  in 
cold  H  Cl,  slight, 
sol.  in  water,  in- 
sol.  in  ether,  sol. 
in  alcohol,   from 
which    it    cryst. 
orange. 
Red-brown. 
Slowly,  slight,  nee- 
dle-form, cryst. 

21.0     Clear  yel.,  amorp. 


GLUCOSIDES  AND  OTHER  NEUTRAL  BODIES :  SOLID. 


144.  ABSINTHIN.     C16H22OB.     A    hard    and    obscurely 
crystalline  solid  of  very  bitter  taste.     Slightly  soluble  in  water, 
very  soluble  in  alcohol,  soluble  in  ether,  and  soluble  in  aqueous 
alkalies.     It  is  precipitated  by  tannic  acid,  not  by  subacetate  of 
lead.     When  treated,  dry,  with  concentrated  sulphuric  acid,  and 
the  mixture  slightly  diluted  with  water,  a  blue-violet  color.     It 
does  not  reduce  potassio  cupric  sulphate,  but  reduces  ammonio 
nitrate  of  silver  to  a  mirror-coating. 

145.  ALOHST.     C17H18O7.     A    crystallizable,    pa.e    yellow 


152  GLUCOSIDES  AND    OTHER   NEUTRAL    SOLIDS. 

solid,  of  neutral  reaction  and  a  taste  at  first  sweet  and  then  very 
bitter.  It  bears  100°  C.  without  change.  It  is  slightly  soluble 
in  cold  water  or  alcohol,  moderately  soluble  in  the  same  when 
hot,  and  soluble  (with  a  yellow  color)  in  the  alkalies  and  their 
carbonates. — Chlorine  gas,  in  a  solution  of  aloin,  forms  a  bright 
yellow  precipitate  (chloraloil) .  Bromine  also  gives  a  yellow 
precipitate. — Concentrated  nitric  acid  transforms  aloin  into 
chrysammic  acid. 

Chrysammic  acid,  C7H2(NO2)2O2,  is  a  yellow  or  greenish- 
yellow  powder,  of  bitter  taste  and  acid  reaction,  sparingly  solu- 
ble in  water,  readily  soluble  in  alcohol  and  in  ether.  It  detonates 
when  heated.  Boiled  with  solution  of  stannous  chloride  it  is 
precipitated  as  a  deep  violet  powder.  Chrysammate  of  calcium 
is  a  dark  red  insoluble  powder. 

146.  AMYGDALIN.     C20H27WOn.     A  white,  pulverulent, 
and  crystalline  solid,  neutral,  without  odor,  and  with  sweet  and 
bitter  taste.     Soluble  in  11  parts  of  water;  sparingly  soluble  in 
cold,  moderately  soluble   in  hot  alcohol ;  insoluble  in  ether. — 
Concentrated  sulphuric  acid  colors  it  light  violet-red.     By  boil- 
ing  dilute    sulphuric  acid,   it   is   transformed  into  oil  of  bitter 
almonds,  glucose,  and  formic  acid ;  by  fermentation  with  emul- 
sin,  into  bitter  almond  oil,  hydrocyanic  acid,  and  glucose.      (16 
parts  of  anhydrous  amygdalin,  as  dried  at  110°  to  120°  C.,  or 
20  to  24  of  ordinary  commercial  amygdalin,  gives  1  part  hydrocy- 
anic acid  and  8  parts  of  bitter  almond  oil.) — Permanganate  of 
potassium  forms  cyanic  and  benzoic  acids. 

147.  ASPARAGIN.     C4H8N2O3(H2O).     Hard  and  brittle  right 
rhombic    (trimetric)    crystals ;   inodorous    and    of   slight    taste. 
Soluble  in  11  parts  cold  or  5  parts  of  boiling  water  (with  slight 
acid  reaction),  insoluble  in  absolute  alcohol,  insoluble  in  ether, 
soluble  in  alkalies  and  acids.     By  fermentation  with  accompany- 
ing extractive  substances,  or  with  casein,  succinate  of  ammonium 
is  formed  (sometimes  with  the  intervening  formation  of  aspartate 
of  ammonium). 


CA  NTH  ARID  IN —  C  UBEBIN.  153 

148.  CANTHABIDIW,     C5H12O2.      A    colorless,    odorless 
solid,  crystallizing  in  rhombic  tables  or  in  needles,  not  volatile 
at  40°  C.,  slightly  volatile  with  water  at  100°  C.,  fusing  and 
subliming  at  about  200°  C.     It  acts  as  a  vesicant  on  the  skin. 
Insoluble  in  cold   or  warm  water,  sparingly  soluble  in  alcohol, 
moderately  soluble  in  ether,  freely  soluble  in   chloroform  and 
benzole,  soluble  in  oil  of  turpentine  and  in  olive  oil.     Cantharidin 
has  the  relation  of  an  acid  of  very  weak  power.     Its  potassium 
compound  is  soluble  in  25  parts  cold  or  12  parts  boiling  water, 
in  3,300  parts  cold  or  110  parts  boiling  alcohol,  insoluble  in  ether 
and  chloroform.      The  barium  cantharidate  is  insoluble  in  water 
and   alcohol,  as  well  as  in  ether  and   chloroform. — Cantharidin 
separations  may  be  effected,  first,  by  solution  in  aqueous  potassa ; 
then,   after   acidulating  with  sulphuric  or  phosphoric    acid,  by 
solution  in  chloroform. 

149.  CATHARTIC   ACID  (of  senna-leaves).     CATHARTIN. 
— An   amorphous    brown    to    black    solid,    soluble    in    aqueous 
alkalies   and  precipitated  from  this   solution  by  acids.     In   its 
natural  condition,  partly  combined  with  calcium  and  magnesium, 
it  is  soluble   in  water  and  insoluble  in  alcohol.     Boiling  dilute 
acids,    in    alcoholic    solution,    convert   it — as   a  glucoside — into 
glucose  and  cathartogenic  acid,  a  brown-yellow  powder,  insoluble 
in  water,  alcohol,  and  ether. 

150.  COLUMBIA.     C21H22O7.     Colombo  bitter. — A  color- 
less solid,   crystallizing  in  trimetric  prisms,  neutral,  inodorous, 
and   extremely    bitter.     It  is   sparingly   soluble  in  cold  water, 
alcohol  and  ether ;  more  freely  in  aqueous  potassa,  being  preci- 
pitated from  the  alkaline  solution  by  addition  of  acids. — Strong 
sulphuric  acid  dissolves  it  with  orange  color,  changing  to  deep 
red,  and  the  addition  of  water  to  this  solution  causes  a  brown, 
flaky  precipitate. 

151.  CTJBEBIN.     C17H16OB.     A    white    solid,    crystallizing 


154  GLUCOSIDES  AND    OTHER   NEUTRAL   SOLIDS. 

in  small  needles,  melting  at  120°  C.,  inodorous,  and  tasteless. 
Slightly  soluble  in  water  and  in  cold  alcohol,  more  soluble  in 
boiling  alcohol,  soluble  in  26  parts  of  ether  and  in  acetic  acid. 
It  is  precipitated  from  alcoholic  solution  by  potassa.  Concen- 
trated sulphuric  acid  colors  it  bright  red,  soon  changing  to 
crimson. 

152.  ELATERIW.     A  colorless  solid,  crystallizing  in  hexa- 
gonal tables,  fusible  ;  insoluble  in  water,  freely  soluble  in  alcohol, 
sparingly  soluble  in  ether.     Precipitated  from  alcoholic  solution 
by  acetate  of  lead  and  nitrate  of  silver.     Soluble  in  sulphuric 
acid   as   a   red  liquid,  giving   a   brown  precipitate  on  dilution 
with  water. 

153.  FRAXTN.      (C16H18O10)2H2O.     A    white    solid,    crys- 
tallizing in  tufts  of  needles  or  right-rhombic  prisms,  of  a  slight 
acid    reaction,   inodorous,   slightly  bitter  and  astringent  to  the 
taste.    It  melts  at  320°  C.,  to  a  red  liquid,  solidifying  amorphous, 
and  dissolving  in  water  with  an  orange  color.     At  a  higher  heat 
it  yields  a  crystalline  sublimate,  the  aqueous  solution  of  which, 
with  ammonia,  shows  a  yellow  fluorescence.     Sparingly   soluble 
in  cold,  freely  in  hot  water,  moderately  soluble  in  alcohol,  slightly 
soluble  in  ether.     The   dilute    aqueous    solution  has  a  blue  or 
blue-green    fluorescence,  favored  by   alkalies  but  prevented  by 
acids.     The    alcoholic    solution    is    likewise    fluorescent.     It    is 
turned  yellow  by  fixed  alkalies  in  aqueous  solution,  or  by  vapor 
of  ammonia  acting  on  the  crystals ;    in  aqueous  solution  ferric 
chloride  causes  a  green  color,  followed  by  a  yellow  precipitate. 
Acetate  of  lead  gives  a  yellow  precipitate.     Boiling  dilute  acids 
resolve  it  (as  a  glucoside)  into  fraxetin  and  glucose.     Fraxetin, 
with  strong  nitric  acid,  shows  successively  dark  violet,  garnet- 
red,  rose-red,  and  yellow  colors,  then  becoming  colorless. 

154.  LACTUCIN.     A  yellowish,  fusible,  bitter  solid  ;  crys- 
tallizable  in  rhombic  plates ;  soluble   in  80  parts  of  cold  water, 


PHI^ORIDZIN:  POPULIN:  QUASSIA.  155 

moderately  soluble  in  alcohol,  sparingly  soluble  in  ether,  soluble 
in  acetic  acid.     Strong  sulphuric  acid  turns  it  brown. 

\\*  £y 

155.  PHLORIDZIN.      C21H24O10.       Crystallizes   in ;  silky 
needles  or  tufts,   slightly  bitter.     Soluble   in   water,  sparingly 
when  cold  but  freely  when  hot ;  soluble  in  alcohol  and  methylic 
alcohol ;  insoluble  in  ether ;  soluble  in  aqueous   alkalies.     Dry 
phloridzin,  treated  with  ammonia  gas,  on  standing  in  the  air, 
becomes,  successively,  orange,  red.  and  blue  (formation  of  phlo- 
rizein).     Strong  sulphuric  acid  colors  it  red.     Dilute  sulphuric 
acid,  by  prolonged  contact,  changes  phloridzin  to  glucose  and 
phloretin.     The  latter  is  an  easily  oxidizable  substance,  dissolv- 
ing in  ammonia,  the  solution  soon  depositing  yellow  scales. 

156.  POPULIN.     C20H22O8.     A  colorless  solid,  of  a  sweet 
taste,  crystallizing  in  silky  needles  (with  2H2O),  which  become 
anhydrous  at  100°  C.  and  melt  at  180°  C.     Populin  dissolves  in 
2,000  parts  of  cold  or  70  parts  of  boiling  water,  in  about  100 
parts  of  absolute  alcohol,  scarcely  at  all  in  ether,  freely  in  mode- 
rately dilute  acids,  also  in  alkalies.     It  is  precipitated  from  its 
acid   solutions   by  alkalies,  from  its  alkaline  solutions  by  acids, 
and  from  its  water  solution  by  common  salt.    With  concentrated 
sulphuric  acid  it  forms  a  deep-red  solution,  from  which  water 
precipitates  a  red  powder,  soluble  in  water  not  acidulated   but 
reprecipitated  by  acids.     Frohde's  reagent  colors  populin  violet. 
Boiling  dilute  mineral  acids  convert  populin,  as  a  glucoside,  into 
benzoic  acid,  saligenin,   and  glucose.     Boiling  with  hydrate  of 
calcium  resolves  populin  into  benzoic  acid  and  salicin. 

157.  QUASSIN.     C10H12O3.     A   colorless,    inodorous,    and 
very  bitter  solid,  crystallizing  in  opaque,  white,  columnar  prisms, 
melting  when  heated.     It  is  soluble  in  about  200  parts  of  water 
of  medium  temperature ;  freely  soluble  in  alcohol,  slightly  solu- 
ble in  ether.     Cold  concentrated  sulphuric  acid  dissolves  it  as  a 
colorless   liquid,    from    which  water  precipitates   it  unchanged. 


156  GLUCOSIDES  AND    OTHER  NEUTRAL   SOLIDS. 

Tannic  acid  precipitates  it,  both  from  aqueous  and  alcoholic  solu- 
tionSj  but  lead  salts  and  mercuric  chloride  do  not  affect  it.  It 
does  not  reduce  ammonio  nitrate  of  silver. 

158.  SARSAPARILLIN.     A  colorless  solid,  crystallizable 
in  needles  ;  soluble  in  water  and  in  alcohol,  soluble  in  ether  and 
in   volatile    oils.     The    solutions    froth    when    shaken.     Strong 
sulphuric   acid   dissolves  it  with  deep  red  color,  changing  to 
violet  and  finally  to  yellow.     From  this  solution  water  precipi- 
tates it  unaltered. 

159.  TARAXACIN.     Crystallizes    in    warty    masses,  of  a 
pleasant  bitter  taste,  fusible,  and  soluble  in  water,  alcohol,  ether, 
and  in  concentrated  acids. 

160.  VANILLIN.     C10H6O2.     Crystallizes  in  long,  colorless, 
four-sided  prisms,  melting  at  76°  C.  (or  82°  C.),  distilling  with 
vapor  of  water,  and  subliming  in  part  at  150°  C.     It  is  neutral 
in  reaction,  and  has   the   characteristic   odor    of  vanilla.     It  is 
nearly  insoluble  in  cold,  moderately  soluble  in  hot  water,  freely 
soluble  in  alcohol,  ether,  and  volatile  oils.     It  dissolves  in  strong 
sulphuric  acid  and  in  potassa. 

161.  Separation  of  the  Glucosides  and  Neutral  Com- 
pounds— described  in  144—160 — by  Water,  Alcohol,  Ether,  and 
Aqueous  Alkalies  (recapitulation)  : 

a.  "Water  dissolves  Absinthin  (sparingly),  Aloin  (hot,  spar- 
ingly), Amygdalin,  Asparagin,  Cathartin,  Columbin  (sparingly  )? 
Cubebin  (slightly),  Fraxin,  Lactucin,  Phloridzin,  Populin  (spar- 
ingly), Quassin  (sparingly),  Sarsaparillin,  Taraxacin,  Vanillin 
(slightly). — Water  does  not  dissolve  Cantharidin,  Cubebin  (ex- 
cept slight  portions),  Elaterin,  Vanillin  (except  slight  portions). 

#.  Alcohol  dissolves  Absinthin,  Aloin,  Amygdalin,  Cantha- 
ridin (sparingly)^  Colombia  (sparingly),  Cubebin  (sparingly), 
Elaterin,  Fraxin,  Lactucin,  Phloridzin,  Populin  (sparingly), 
Quassin,  Sarsaparillin,  Taraxacin,  Vanillin. — Alcohol  does  not 
dissolve  Asparagin,  Cathartin. 


ALB  UMENOIDS.  1 57 

c.  Ether  dissolves  Absinthin,  Aloin  (sparingly),  Cantharidin, 
Cubebin,    Elaterin    (sparingly).    Lactucin   (sparingly),   Sarsapa- 
rillin,  Taraxacin,  Vanilliu. — Ether  does  not  dissolve  Amygdalin, 
Asparagin,  Fraxin  (except  slight  portions),  Phloridzin,  Populin, 
Quassin  (except  slight  portions). 

d.  Aqueous  alkalies  dissolve  Absinthin,  Aloin,  Asparagin, 
Cathartin,    Colombin,    Phloridzin,    Populin,    Vanillin ;    do   not 
dissolve   Cubebin. 

[For  Dragendorff 's  elaborate  process  for  separation  and  identification  of 
Foreign  Bitters  in  Beer,  see  Arch.  Pharm.  (3),  iii.,  295  ;  iv.,  389  ;  or  Jour. 
Chem.  Soc.,  1874,  p.  818  ;  or  Prescott's  Exam.  Alcoholic  Liquors,  N.  Y.,  1874.] 


NITROGENOUS  NEUTRAL  BODIES. 

162.  ALBUMENOIDS.  Varieties  of  Albumen,  Fibrin,  and 
Casein. — Characterized  as  infusible,  non- volatile,  amorphous 
solids,  neutral  in  reaction  and  indifferent  to  combination ;  in 
natural  condition,  soluble  in  water  containing  alkalies  or  contain- 
ing certain  salts  of  alkalies  ;  rendered  insoluble  in  water  by  acids, 
and  generally  by  heat  in  absence  of  dissolving  agents,  and  by 
salts  of  certain  heavy  metals.  Farther,  they  give  a  reaction  for 
nitrogen  («),  and  color-tests  with  strong  hydrochloric  acid  (#), 
and  with  mercuric  nitrate  in  nitric  acid  (c),  and  act  as  reducing 
agents  (d) . — Albumenoids  are  distinguished  and  partly  separated 
from  Gelatin,  Gums,  and  Dextrin,  by  their  coagulation  witk 
heat  or  with  mineral  acids ;  they  are  separated  from  starch  by 
dissolving  in  solution  of  alkali  too  dilute  to  affect  the  starch 
(see  176,  /). 

a.  Mix  the  well-dried  substance  with  dry  soda-lime,  intro- 
duce into  a  hard-glass  long-necked  matrass  (or  long  and  narrow 
test-tube),  place  a  slip  of  red  litmus-paper  in  the  mouth,  and 
heat,  gradually,  to  incipient  carbonization.  Production  of  am- 
monia (this  base  being  absent  in  the  substance)  indicates  a  nitro- 


158  ALBUMENOIDS. 

genous  organic  body. — Albumenoids,  on  boiling  with  potassa 
solution,  yield  ammonia ;  a  farther  quantity  being  obtained  by 
adding  permanganate  (WANKLYN). 

b.  Strongest  hydrochloric  acid  dissolves  albumenoids  to  a 
yellowish  color,  which  becomes  blue  or  violet  by  exposure  to 
the  air. 

c.  Acid  mercuric  nitrate  solution — prepared  by  dissolving 
one  part  of  mercury  in  two  parts  of  nitric  acid  of  spec.  grav.  1 .42 
— on  digestion  with  solid  albumenoids,  at  60°  to  100°  C.  (140° 
to  212°  F.),  gives  a  deep  red  color.     If  the  substance  tested  is  in 
solution,  it  should  be  concentrated,  and  used  in  such  small  pro- 
portion that  the  reagent  is  not  much  diluted. 

d.  Alkaline  cupric  solution  is  turned  violet  by  albumenoids, 
and  on  warming  the  cuprous  oxide  is  quickly  reduced.     Solution 
of  permanganate  is  also  reduced  by  albumenoids. 

Under  the  Microscope,  albumenoids  are  turned  yellow  by 
iodine,  and  purple-violet  by  sulphuric  acid  with  sugar. 

163.  OVALBUMEN.     Soluble   in   water    with   some  turbidity 
and  suspension  of  skinny  particles  ;  this  solution  being  rendered 
nearly  clear  by  alkalies  or  alkaline  carbonates  or  common  salt. — 
Chemically  neutral  water  solutions  are  coagulated  by  heating  to 
a  very  little  above  63°  C.  (145°  F.) ;  by  alcohol,  carbolic  acid, 
and  creosote ;    by    ether  (but   not   completely),  by  nitric   acid 
(quickly  and  completely),  by  hydrochloric  acid  (slowly  redissolv- 
ing  when  the  acid  is  strong),  and  by  sulphuric  acid  (slowly).    Salts 
of  silver,  mercury,  etc.,  coagulate  it;  also    alum.     Acetic   and 
tribasic  phosphoric  acids  do  not  coagulate  it,  but  (by  neutraliz- 
ing the  natural  alkali)  they  render  its  pure  water  solution  still 
more  turbid.     Tannic  acid  coagulates  it  quickly. — Strong  potassa, 
or  soda,  gelatinizes  albumen. 

For  weighing,  albumen  is  precipitated  from  slightly  acidu- 
lated solutions  by  boiling,  washed  with  water,  and  dried  first 
below  50°  C.  (122°  F.),  then  at  100°  C.  (So  treated,  it  is  not 
rendered  insoluble.) 

164.  SERALBUMEN.     Dissolves  in  water  with  some  turbidity. 


DETERMINATIONS  IN  MILK.  159 

Coagulated  at  75°  C.  (167°  F.),  or,  in  presence  of  alkaline  salts, 
at  a  higher  temperature,  while  in  presence  of  acetic  acid  a  lower 
temperature  suffices.  Coagulated  by  dilute  mineral  acids,  slowly 
or  if  heated  quickly ;  redissolved  by  strong  nitric  acid  and 
(readily)  by  hydrochloric  acid.  Coagulated  by  alcohol ;  not  by 
ether  (distinction  from  Ovalbumen). — Coagulated  by  salts  of 
mercury  and  silver. — Aqueous  alkalies  dissolve  coagulated  seral- 
bumen. 

165.  CASEIN.     In  natural  condition,  dissolved  clear  by  water. 
Coagulated  by   rennet    (separation  from    milk   albumen)  ;    by 
moderately  dilute  acetic  acid  (separation  from  ovalbumen,  seral- 
bumen,  milk  albumen) ;  by  ether  and  by  mineral  acids  and  mer- 
curic chloride.     Not  coagulated  by  dilute  alcohol  or  by  boiling 
(separation  from  seralbumen  and  from   ovalbumen).     Alkalies 
and  strong  acids,   even  strong  acetic  acid,  dissolve  coagulated 
casein.     [Farther,  see  Phar.  Jour.,  1874,  Sept.  5,  p.  188.] 

166.  MILK  ALBUMEN.     (0.3  to  0.5  percent,  of  healthy  cows' 
milk ;  found  as  high  as  3  to  10  per  cent,  in  diseased  milk  and  in 
the  colostrum.) — Not  coagulated   by  rennet,  but  coagulated  by 
boiling,  after  the  slightest  acidulation  with  acetic  acid  (two  means 
of  separation  from   Casein).     Coagulated  by  mineral  acids  and 
salts  of  heavy  metals  ;  the  coagulum  being  soluble  in  alkalies. 

167.  Determination  of  Casein  and  Albumen  in  Milk. — 
a.  Take  50  grams  of  milk,  add   an  equal  quantity  of  water,  add 
rennet,  set  aside  at  40°  to  50°  C.      Gather  the  precipitate   (the 
casein  with  most  of  the  fats)  in  a  tared  filter,  wash  with  water, 
then  with  alcohol,  then  with  ether  thoroughly,  dry  at  110°  C., 
and  weigh  as  Casein. — To  the  nitrate  from  the  curd  (and  first 
water  washings),  add  4    or   5    drops    of  acetic   acid   and    boil. 
Gather  the  coagulum   in  a  tared  filter,  wash  with  water,  dry  at 
110°  C.,  and  weigh  as  Albumen.— (The  filtrate  from  the  curd  of 
albumen  is  saved  for  determination  of  the  Sugar,  according  to 
187,  I     This  filtrate  contains  a  minute  proportion  of  an  album e- 
noid  called  Lacto-protein,  which  is  coagulated  by  mercuric  nitrate 
— not  by  nitric  acid.) 


1 60  ALB  UMENOIDS. 

168.  Quantitative  Analysis  of  Milk. 

(1)  Determine  the  Total  Solids,  as  directed  in  64,  b. 

(2)  Determine  the  Fats,  as  directed  in  64,  #  (or  a). 

(3)  Determine  the  Casein  and  Albumen,  as  directed  in  167. 

(4)  Determine  the  Sugar,  from  the  nitrate  of  167,  according 
to  187,?. 

(5)  Determine  the  Salts    (soluble    and  insoluble    in  water). 
Evaporate  20  grams  in  a  tared  dish,  with  a  tared  small  glass  rod, 
ignite  to  whiteness  (by  triturating)  ;  weigh,    then  extract  with 
water  and  dry  and  weigh  the  residue. 

169.  Commercial  Examinations  of  Milk  usually  require, 
more  especially,  the  following  operations  : 

(1)  Find  the  volume  per  cent,  of  cream.     (Or  use   a  lacto- 
scope — 64,  c.) 

(2)  Take   the   specific   gravity,    an4    consider   the   relation 
between  this  and  the  amount  of  cream.     Skimmed  milk  has  a 
specific  gravity    about    0.004    greater    than    entire    milk    (from 
CHANDLER'S  averages.) 

(3)  For   more  exact  data,   find   the  solids    minus  fats,    as 
directed  in  (1)  and  (2)  of  168.     The  "  solids  not  fat"  is  nearly 
the  same  proportion  of  the  milk  of  different  cows — also,  of  the 
whole  milk,  the  skim  milk,  and  the   cream,  alike   (WANKLYN). 
Hence,  variation  in  this  quantity  indicates  sophistication. 

(4)  Examine  with  the  microscope   (presence   of   colostrum 
globules  usually  coinciding  with  excess    of  albumen),  and  test 
for  impurities  in  general. 

170.  GELATIN.  (Isinglass,  Glue,  "  Gelatin.")  An  infusible, 
non-volatile,  amorphous,  horny  solid;  colorless  to  yellowish, 
translucent,  brittle,  odorless,  and  tasteless. —  Characterized  as  a 
neutral  and  indifferent  substance,  evolving  ammonia  freely 
when  heated  dry  with  soda-lime  or  when  boiled  with  potassa 
solution  and  permanganate  (see  Albumenoids,  162,  «),  and 
existing  in  a  soluble  and  an  insoluble  condition. — Its  soluble 
form  dissolves  very  slowly  and  slightly  in  cold  water,  gradually 


CARBOHYDRATES.  161 

and  completely  in  boiling  water,  the  solution  if  not  very  dilute 
congealing  into  a  tremulous  jelly-like  mass  when  cold  (distinc- 
tion from  Albumenoids  which  are  coagulated  by  boiling).—* 
Gelatin  solution  is  coagulated  by  alcohol,  by  mercuric  chloride, 
by  chlorine  gas,  and  especially  by  tannic  acid  (formation  of 
leather)  (the  last,  a  separation  from  Gum  arabic  and  Dextriu)i 
In  distinction,  and  separation  from  Albumenoids,  it  is  not  pre- 
cipitated  by  nitric,  hydrochloric,  or  sulphuric  acids,  or  by  saltf 
of  silver,  copper,  lead,  iron,  or  aluminum.  In  not  being  precipi- 
tated by  basic  acetate  of  lead,  it  is  separated  from  Dextrin, 
soluble  starch,  starch-paste,  and  Gums. — Gelatin  solution  dis- 
solves the  recent  cupric  hydrate,  as  formed  in  cupric  sulphate 
solution  by  excess  of  potassa,  turning  the  color  to  dark  violet, 
which  on  warming  becomes  red,  without  precipitation  of  cuprous 
hydrate.  It  promptly  reduces  permanganate  solution. 

100  parts  of  gelatin,  as  dried  at  130°  C.,  by  precipitation 
with  tannic  acid,  yield  about  135  parts  of  leather  precipitate. 

171.  LEATHER  yields  its  tannic  acid  to  boiling  dilute 
alcohol,  the  gelatin  remaining  coagulated.  The  dried  and  finely- 
rasped  leather  is  first  freed  from  oils  and  resins  by  digestion  with 
ether  free  from  alcohol,  along  with  water.  Untanned  gelatin 
may  be  detected  in  leather,  by  the  translucence  of  thin  shavings 
(of  the  central  portion),  and  by  yielding  a  solution  of  gelatin 
when  long  macerated  with  water  at  about  90°  C. 


CARBOHYDRATES. 

172.  GUMS.  Mostly  C6H10O5  (as  an  anhydride)  in  com- 
bination with  alkaline-earthy  bases  or  with  water.  Characterized 
as  infusible  and  non-volatile,  amorphous  substances,  destitute  of 
nitrogen,  more  or  less  perfectly  soluble  in  water,  insoluble  in 


162  CARBOHYDRATES. 

absolute  alcohol,  ether,  benzole,  etc. ;  precipitated  by  subacetate 
of  lead ;  and  not  readily  transformed  to  glucose  by  boiling  with 
dilute  acids  (a  distinction  from  Dextrin  and  from  Starch). 

173.  GUM  ARABIC.     Gum  Acacia.     Arabin,  or  Arabates  of 
calcium,  magnesium,  potassium,  etc. — Soluble   (by  digestion)  in 
2  parts  of  water,  forming  a  syrupy  liquid  of  spec.  grav.  1.13, 
which  mixes  clear  with  2£  times  its   volume  of  35  per  cent, 
alcohol.     Soluble  in  20  to  25  parts  of  45  per  cent,  alcohol.     If 
acidulated    (with   mineral    or   acetic   acids),  arabic   acid    being 
liberated,  it  is  much  less  soluble  in  dilute  alcohol,  i.e.  requires 
for  solution  alcohol  more  dilute. 

Gum  arabic  is  characterized  by  a  white  precipitate  by  sub- 
acetate  of  lead  or  ammoniacal  acetate  of  lead,  in  very  dilute  solu- 
tions ;  by  giving  (with  oxalate)  the  reactions  of  calcium  (distinc- 
tion from  Dextrin  and  Starch) ;  by  forming  an  almost  insoluble 
jelly  when  in  saturated  solution  it  is  treated  with  about  -^ 
volume  of  concentrated  solution  of  ferric  chloride,  and  by  pre- 
venting the  precipitation  of  iron  salts  by  alkalies  when  in  dilute 
solution  (two  points  of  distinction  from  Dextrin). 

As  a  reducing  agent,  fresh  solution  of  gum  arabic,  with  potas- 
sio  cupric  solution,  precipitates  the  cuprous  hydrate  after  heating 
to  100°  C.  (Dextrin  effecting  this  reduction  at  a  gentle  heat). 
Stale  solution  of  gum  arabic  generally  contains  glucose- 
Gum  arabic  gives  no  precipitate  with  tannic  acid  (separa- 
tion from  Gelatin  and  Ovalbumen)  ;  or  with  mineral  acids 
(separation  from  Albumenoids) ;  and  no  reaction  with  iodine 
(distinction  from  Starch). 

Sulphuric  acid,  added  to  its  one-half  volume  of  concentrated 
acacia  gum  solution,  turns  it  brown  to  black.  Boiling  with  dilute 
sulphuric  acid  slowly  transforms  gum  acacia  (in  part)  to  glucose. 
Ordinary  gum  arabic,  at  90°  to  100°  C.,  loses  10  to  15  per 
cent,  of  moisture ;  above  100°  C.,  it  is  so  altered  as  to  be  imper- 
fectly soluble. 

174.  GUM  TRAGACANTH  is  only  in  small  part  directly  soluble 
in  water,  in  which  it  swells  to  a  jelly  ;  the  greater  part  dissolving 


DEXTRIN  :   STARCH.  163 

by  long  boiling.  The  solution  so  formed  consists  chiefly  of 
Arabin,  with  a  very  little  Glucose,  and  gives  reactions  for  these 
substances,  according  to  their  proportion.  Boiling  with  dilute 
sulphuric  or  hydrochloric  acid  dissolves  the  gum  more  rapidly 
than  with  water,  producing  a  little  larger  proportion  of  glucose. 
— The  residue  not  soluble  in  pure  water  contains  starch,  and  is 
colored  blue  by  iodine. 

175.  DEXTRIN.    British   Gum.  C6H10O6.— A  yellow-white 
to    colorless    amorphous    solid;     tasteless    and    odorless.     It   is 
soluble  in   about  one  part  of  water,   to   a  syrupy   semi-liquid, 
which  is  miscible  with  1-J  volumes  of  60  per  cent,  alcohol  or 
with  3  volumes  of  50  per  cent,  alcohol.     It  is  insoluble  in  90  per 
cent,  alcohol,  sufficient  of  which  precipitates  it  from  solutions  not 
too    dilute ;    and   insoluble   in  ether,  chloroform,  bisulphide  of 
carbon,  etc. — Commercial   dextrin   almost  always   contains  glu- 
cose ;  frequently  contains  "  soluble  starch "'  (15  per  cent,  of  which 
is  held  not  objectionable)  ;  and  is  sometimes   brown  from   pre- 
sence of  caramel. 

Concentrated  sulphuric  acid  dissolves  dry  dextrin,  without 
color  in  the  cold  but  with  blackening  when  warmed. — Subacetate 
-or  ammoniacal  acetate  of  lead  precipitates  dextrin  from  very 
dilute  solutions  (in  cold  and  dilute  solution,  a  distinction  from 
Glucose). — Pure  dextrin  (free  from  glucose)  reduces  potassio 
cupric  sulphate  at  80°  to  90°  C.  It  does  not  reduce  boiling 
solution  of  cupric  acetate  (distinction  from  Glucose). — Pure  dex- 
trin is  not  colored  by  iodine  (distinction  from  Starch  and  "  solu- 
ble starch  ")  ;  nor  precipitated  by  tannic  acid  (separation  from 
Starch  and  soluble  starch,  Gelatin,  and  Ovalbumen)  ;  nor  by 
mineral  acids  (separation  from  Albumenoids) ;  nor  by  baryta 
water  (separation  from  Soluble  Starch). 

Dextrin  is  dried  (over  a  glycerin-bath)  at  110°  C.  Its  preci- 
pitate by  subacetate  of  lead  is  Pb  C6H10O6. 

176.  STARCH.    Chiefly  C6H10O5 ;  being  an  organized  body, 


164  CARBOHYDRATES. 

of  many  varieties  of  structure,  and  containing  cellulose  in  the 
envelopes  of  the  granules. — Varieties  of  starch  are  identified  by 
their  form  under  the  microscope  (a).  Starch  in  general  is 
characterized  by  its  relations  to  solvents  (b)  ;  its  color  with 
iodine  (c) ;  its  precipitates  with  tannic  acid,  subacetate  of  lead, 
and  baryta  (d)  ;  and  its  easy  transformation  to  "  soluble  starch/' 
dextrin,  and  then  glucose  (e) . — Starch-paste  and  "  soluble  starch," 
both,  are  distinguished  and  in  part  separated  from  Albumenoids 
by  non-precipitation  with  heat,  or  with  mineral  acids  (e) ;  from 
Gelatin  by  precipitation  with  subacetate  of  lead  (d) ;  from  Gums 
by  precipitation  with  tannic  acid,  and  from  Dextrin  by  precipita- 
tion with  tannic  acid  or  with  baryta  water  (d).  The  complete 
separation  of  starch  from  Albumen,  Gelatin,  or  Gum  is  effected 
by  first  changing  it  to  glucose  (c)  and  then  washing  the  latter 
away  (from  the  coagulum)  with  strong  alcohol. — Starch  is  sepa- 
rated from  Grains  or  other  parts  of  Plants  by  water-washing 
(f),  and  determined  directly  or  as  glucose  (</). 

a.  The .  starch  granules  are  from  3-^  to  -^  inch  in  diame- 
ter, flattened   and  ovate,  with  concentric  rings  (the  borders  of 
overlapping  layers),  and  mostly  with  a  small  eccentric  nucleus. 
They  are  characteristic  of  each  variety. 

b.  Natural  starch  is  insoluble  in  water,  alcohol,  ether,  etc. 
Water  at  60°  to  75°  C.  (140°  to  167°  F.)  bursts  the  granules  of 
natural  starch ;  a  small  part  of  which  is  apparently  dissolved,  the 
larger  part  remaining  suspended  in  minute  particles  forming  a 
gelatinous  semi-solution,  while  a  small  portion,  consisting  of  the 
envelopes,  readily  subsides,  the  whole  being  known  as   Starch- 
paste.     Boiling  water   slowly  changes  starch-paste  to  "soluble 
starch  "  and  to  Dextrin. — Caustic  potassa  solution  of  2  or  3  per 
cent,  causes  starch  to  swell  to  starch-paste ;  finally  forming  some 
"  soluble  starch." — When  starch  is  triturated  with  two-thirds  its 
weight  of  concentrated  sulphuric  acid,  in  the  cold,  and  left  for 
an  hour,  then  washed  on  a  filter  with  alcohol  till  free  from  acid, 
it  is  transformed  into  "  Soluble  Starch" 

This  is  a  modification  of  starch,  soluble  in  cold  or  hot  water 


STARCH.  165 

to  a  syrupy  liquid  not  quite  so  clear  as  dextrin ;  colored  blue  to 
violet  with  iodine  (distinction  from  Dextrin) ;  precipitated  by 
alcohol  when  the  latter  is  as  much  as  50  per  cent,  (dextrin  re- 
quires stronger  alcohol  for  precipitation) ;  precipitated  by  tannic 
acid  and  by  baryta  water  (two  ways  of  separating  from  dextrin) ; 
precipitated  by  subacetate  of  lead  (coinciding  with  dextrin). 

Concerning  solution  of  starch  by  its  transformation  into  Dex- 
trin and  Glucose,  see  e. 

c.  Free  iodine — in  solution  with  water  or  alcohol  or  water 
with  iodide,  or  in  vapor — colors  starch  blue  to  violet,  forming 
the  "  iodide  of  starch  "    (a  product  of  adhesion) .      The  color  is 
destroyed  by  heating  (returning  when  cold),  by  washing  with 
alcohol,  and  by  chlorine,  potassa,  hydrosulphuric  acid,  or  other 
agents  which  bring  the  iodine  into  chemical  combination. 

d.  Tannic    acid    precipitates    starch-paste ;  the    precipitate 
being  soluble  in  excess  of  the  starch,  and  soluble  by  heat — sepa- 
rating again  when  cold.     Baryta  water,  and  solution  of  subacetate 
of  lead  or  ammoniacal    solution  of  acetate  of  lead,  precipitate 
starch-paste  (as  well  as  soluble  starch). 

e.  Starch  is  changed  to  Glucose  (through  soluble  starch  and 
dextrin)  very  quickly  by  boiling  dilute  mineral  acids  (two  to 
three  per  cent.);  very  slowly  by  boiling  with  water,  and  quite 
effectually  by  the  conditions  of  the   alcoholic  and  "  saccharine " 
fermentations. 

f.  Cereal  grains,  or  other  parts  of  plants,  are  finely  pulver- 
ized, and  then  washed  on  a  hair  sieve  with  cold  water,  and  the 
washings   allowed  to  subside  (as   in  manufacture).     The  starch 
residue  may  be  washed  again  through  a  bag  of  fine  linen.     The 
residue  is  then  washed  on  a  filter  with  45  per  cent,  alcohol  con- 
taining 0.1  per  cent,  potassa,  then  with  60  per  cent,  alcohol,  then 
with  ether  ;  and  dried,  first  below  60°  C.,  lastly  at  100°  to  110° 
C.,  when  it  may  be  weighed,  as  starch. 

g.  Starch  may  be  determined  as  Glucose  (187,  J),  after  boil- 
ing with   dilute  sulphuric  acid  (e)  and  neutralizing.     C6H12O6  : 
CJI  O   :  :  180  :  162. 


166  CARBOHYDRATES. 

177.  PECTOUS  SUBSTANCES.     Vegetable  products  cor- 
responding in  properties  to  the  gelatinoids  of  the  animal  king- 
dom. 

178.  PECTOSE.     Insoluble  in  water,  alcohol,  or  ether.     Dis- 
solved as  Pectin,  etc.,  by  long  boiling  with  water,  more  readily 
with  vegetable  acids.     Hot  dilute  mineral  acids  dissolve  pectose 
as   Pectin,   which   by   longer   treatment    becomes    Metapectin. 
Alkalies,  by  hot  aqueous  digestion,  form  soluble  salts  of  Meta- 
pectic  acid. 

179.  PECTIN.     Neutral ;  soluble  in  cold  or  hot  water;  gela- 
tinized by   dilute  alcohol    and  precipitated  by  strong  alcohol ; 
changed  by  hot  mineral  acids  to  Metapectic  acid  ;  changed  by 
cold  dilute  alkalies  into  soluble  salts  of  Pectic  acid,  by  hot  and 
strong  alkalies  into  soluble  salts  of  Metapectic  acid. 

180.  PECTIC  ACID.     In  its  moist  state,  gelatinous.     Neutral 
in   reaction.      Insoluble   in   cold    and    scarcely    soluble    in    hot 
water;  by  boiling  water  slowly  changed  to  soluble  Parapectic 
acid,  afterward  to  Metapectic  acid.     Pectic  acid  jelly  is  hardened 
and  parapectic  acid  solution  is  precipitated  by  alcohol  and  by 
solution  of  sugar.     Boiling  with  dilute  acids  readily  converts 
pectic  acid  to  Metapectic  acid.     Alkalies,  on  contact  with  pectic 
acid,  form  pectates  soluble  in  water  but  insoluble   in   alcohol. 
The  pectates  of  non-alkaline  metals  are  insoluble  in  water.     Boil- 
ing with  aqueous  alkalies  converts  pectic  acid  into  soluble  salts 
of  Metapectic  acid. 

181.  PARAPECTIN  is  neutral,  soluble  in  water,  insoluble  in 
alcohol,  by  which  its  aqueous  solution  is  gelatinized.     Boiling 
dilute    acids    convert    parapectin     into    Metapectin.     Aqueous 
alkalies,  on  contact  with  parapectin,  form  soluble  salts  of  Pectic 
acid. 

182.  PARAPECTIC  ACID  is  soluble  in  water  (with  acid  reaction), 
the  solution  changing  into  one  of  Metapectic  acid.      Parapectic 
acid  is  precipitated  from  water  solution  by  strong  alcohol.     It 
forms  soluble  salts  with  the  alkalies ;  insoluble  salts  with  the 
other  metallic  bases. 


CELLULOSE.  167 

183.  METAPECTIN  is  soluble  in  water  (with  acid  reaction), 
insoluble  in  alcohol.     Alkalies  form  with  it  the  soluble  salts  of 
Pectic  acid. 

184.  METAPECTIC  ACID  is  producible  from  all  pectous  sub- 
stances, but  produces  none  of  them.     It  is  soluble  in  water  (with 
acid  reaction) ;  soluble  in  alcohol  (separation  from  all  other  pec- 
tous substances)  ;  and  forms  soluble  normal  salts  with  all  the  bases 
(the  non-alkaline  salts  of  other  pectous  acids  being  insoluble.) 

Solution  of  subacetate  of  lead  precipitates  all  the  pectous 
substances  (including  metapectic  acid).  Hot  potassio  cupric  solu- 
tion is  reduced  by  all  the  pectous  substances.  They  are  but 
slightly  or  not  at  all  changed  to  Glucose,  by  boiling  dilute  acids. 

185.  CELLULOSE.     (C6H10O5)w.     Characterized   by    its 
physical  properties  and  relations  to  solvents   (a) ;  by  its  trans- 
formation into  parchment-paper  (#),and  into  dextrin  and  glucose 
(c),  and  by  its  formation  of  gun-cotton  (d).  •  It  is  separated  from 
Starch  by  its  solubility  in  ammonio  cupric  solution  (a),  and  by 
its  insolubility  in  hot  dilute  acids. 

a.  Pure  cellulose  is  a  white,  translucent  solid ;  of  specific 
gravity  about  1.5;  insoluble  in  water,  alcohol,  ether,  oils,  and 
other  neutral  solvents.  It  is  slowly  disintegrated  and  partly  dis- 
solved with  decomposition  by  strong  aqueous  alkalies.  Hot 
dilute  mineral  acids  scarcely  affect  it ;  moderately  dilute  nitric 
acid  changing  it  to  Xyloidin. — Finely  divided  cellulose  slowly 
dissolves  in  a  solution  of  oxide  of  copper  in  strong  ammonia ; 
being  precipitated  therefrom  unchanged  by  hydrochloric  acid. — 
Fibres  of  cellulose,  superficially  softened  by  sulphuric  acid,  or 
by  potassa  solution,  are  colored  violet  to  blue  by  iodine  solution, 
and  are  by  this  means  rendered  distinctly  visible  under  the 
microscope.  Also,  by  dipping  in  a  1  per  cent,  solution  of  potas- 
sium iodide  and  drying,  then  immersing  in  strong  sulphuric  acid 
and  washing  with  water,  cellulose  is  converted  into  a  blue  sub- 
stance, showing  red  and  blue  globules  under  the  microscope 
(TERRELL). 


168  CARBOHYDRATES. 

b.  Sulphuric  acid  of  about  1.5  or  1.6  spec,  grav.,  acting  for  a 
very  short  time  on  cellulose  (unsized  paper),  changes  its  state  of 
aggregation  so  as  to  form  parchment-paper. 

c.  Concentrated  sulphuric  acid,  in  the  cold,  slowly  dissolves 
(thoroughly  dry)    cellulose  to  a   colorless  syrup,  which  closely 
resembles  dextrin.     It  is,  however,  colored  blue,  or  after  stand- 
ing some  days  in  the  acid,  violet  to  brown,  by  iodine.     The  name 
amyloid  has  been  applied  to  this  substance.     If  it  is  now,  after 
several  days'  contact  of  the  acid,  diluted  with  30  or  40]  parts  of 
water  and  boiled  (until  a  portion  is  not  precipitated  by  strong 
alcohol),  it  is  wholly  converted  into  glucose. 

d.  Nitric  acid  of  spec.  grav.  1.5,  or  a  mixture  of  nitrate  of 
potassa  2  parts  and  concentrated  sulphuric  acid  3  parts,  at  a  tem- 
perature below  50°  C.  (122°  F.),  converts  clean,  dry  cotton  wool 
(finely  divided  cellulose),  by  24  hours'  contact,  into  nitrocellulose. 
This  is  washed  first  with  cold  water,  then  with  hot  water,  lastly 
with  alcohol  and  dried  at  ordinary  temperature. 

186.  NITROCELLULOSE,  Pyroxylon,  or  Gun  Cotton  is  the  sub- 
stitution of  (NO2)7_9  for  H9_7  in    C18H30O15 — ,  the  lower  substi- 
tutions being  most  soluble  in  ether,  the  higher  substitutions  being 
most  explosive.     It  is  more  readily  soluble  in  alcoholic  than  in 
pure  ether — formation  of  Collodion.     It  is  not  attacked  by  dilute 
acids  or  alkalies  :  strong  sulphuric  acid  dissolves  it  slowly,  strong 
alkalies  dissolve  it  with  decomposition. — The  residue  from  collo- 
dion is  unchanged  pyroxylon,  in  a  firm  and  elastic  mass,  capable 
of  being  moulded  at  about  140°  C. 

187.  GLUCOSE.      C6H12O6.H2O.      Grape   sugar.      Starch 
sugar.     Dextrose. — Characterized  by  its  physical  properties  and 
solubilities  (a)  ;  its  rotation  of  polarized  light  (b)  ;  its  reactions 
with  potassa  (c)  and,  as  a  reducing  agent,  with  potassio  cupric 
solutions  (d),  cupric  acetate  (e),  ferricyanide  of  potassium  (/), 
ammonio  silver  nitrate  (g),  bismuthic  subnitrate  (A),  and  molyb. 
date  of  ammonium  (i).     It  precipitates  ammoniacal  acetate  of 
lead  (j),  and  reacts  with  stannic  chloride  and  cobaltous  hydrate 


GLUCOSE.  169 

(&). — From  Sucrose,  it  is  distinguished  by  a  stronger  reducing 
power  (d,  e,  f,  g,  i),  by  not  blackening  with  concentrated  sul- 
phuric acid  (189,  c),  but  turning  brown  with  potassa  solution  (c). 
— From  lactose,  it  is  distinguished  by  stronger  reducing  power 
(e,  i},  less  soluble  precipitate  with  ammoniacal  acetate  of  lead  \ 
(j),  and  by  not  blackening  with  concentrated  sulphuric  acid. — 
From  Fructose,  it  is  separated  by  crystallization,  and  distin- 
guished by  contrary  rotation  (b). — It  is  separated  from  Dextrin, 
Soluble  Starch,  Gums,  the  Pectous  substances  save  metapectic 
acid,  Gelatin,  and  Albumenoids,  by  solution  in  90  per  cent, 
alcohol  (a)  ;  from  Fats,  etc.,  by  insolubility  in  ether. — It  is 
determined  by  the  volumetric  solution  of  potassio  cupric  salt 
(I),  or  by  the  polariscope  (b),  or  by  fermentation  (m). 

a.  Glucose   crystallizes,  with  some   difficulty,    in   warty   or 
cauliflower-like   masses,  hydrated ;  but  from  strong  alcohol,  in 
anhydrous  needles.     At  60°  C.,  the  hydrate  becomes  an  anhy- 
drous, white  powder;  at  100°  C.,  the  hydrate  melts  to  a  trans- 
parent mass;  but  the  anhydrous  glucose  melts  at  130°  C.     For 
weighing,  it  should  be  well  dried  at  60°  C.,  then  at  110°  C. 
(without  melting). — Glucose  is  soluble  in  a  little  more  than  one 
part  of  cold  water ;  a  saturated  solution  having  a  spec.  grav. 
1.206  and  containing  45  per  cent,  of  anhydrous  glucose.     Dilute 
alcohol  dissolves  it  freely  ;  100  parts  of  90  per  cent,  alcohol  dis- 
solve 2  parts  in  the  cold,  20  parts  with  boiling ;  in  cold,  absolute 
alcohol  it  is  scarcely  at  all  soluble.     Insoluble   in  ether,   chloro- 
form, oils ;  soluble  in  60  parts  hot  amylic  alcohol ;  soluble  in 
methylic  alcohol. 

b.  Anhydrous  glucose  has  a  specific  rotatory  power  of  55° 
(Pasteur)  to  the  right. 

c.  Potassa,  or  milk  of  lime,  when  warmed  in  solution  of 
glucose,  causes  a  reddish-yellow  to  brown  color  with  deposition 
of  a  humus-like  substance  (distinction  from  Sucrose). 

d.  The   test   for   reduction  of  cupric   hydrate   to   cuprous 
hydrate  in  presence  of  alkali  may  be  made  by  adding  a  drop  or 
two  of  cupric  sulphate  solution  and  then  an  excess  of  potassa,  or 


170  CARBOHYDRATES, 

by  use  of  enough  of  the  standard  solution  specified  in  k  to  tinge 
the  test-liquid  bluish.  At  a  gentle  heat  (short  of  boiling)  glu- 
cose throws  down  the  brownish-yellow  precipitate  of  cuprous 
hydrate,  changed  by  boiling  to  a  brownish-red  precipitate  of 
cuprous  oxide.  Without  heat,  the  reduction  occurs  after  standing 
some  time.  (Compare  Sucrose,  b.) 

e.  Solution  of  cupric  acetate  is  reduced  by  glucose  on  boil- 
ing (distinction  from  Sucrose  and  from  Lactose — the  latter  effect- 
ing a  slight  reduction  after  long  boiling). 

/.  Ferricyanide  of  potassium  (1  part)  in  solution  with 
potassa  (J  part),  at  80°  to  100°  C.,  is  reduced  by  glucose  to  ferro- 
cyanide.  The  reduction  is  shown  by  Iqss  of  color,  and  by  a 
blue  precipitate  with  ferric  salt.  (Distinction  from  Sucrose  and 
from  Dextrin.) 

g.  Boiling  solution  of  glucose  separates  silver  (black)  from 
nitrate  of  silver;  more  readily  blackens  the  recent  oxide  of 
silver,  and  gives  a  dirty  gray  precipitate  in  solution  of  ammonio 
nitrate  of  silver  (the  latter  a  means  of  distinction  from  Sucrose). 

h.  Basic  bismuthic  nitrate,  with  carbonate  of  sodium,  is 
reduced  by  boiling  solution  of  glucose,  with  precipitation  of  bis- 
muthous  oxide  as  a  dark  gray  sediment. 

i.  Solution  of  molybdate  of  ammonium,  at  boiling  heat,  is 
reduced  by  glucose,  with  formation  of  the  blue  molybdic  molyb- 
date (distinction  from  Sucrose,  Lactose,  and  Dextrin). 

j.  Ammoniacal  acetate  of  lead  solution  is  precipitated  by 
addition  of  concentrated  solutions  of  glucose,  the  precipitate  dis- 
solving in  excess  of  glucose  solution,  but  appearing  again  on 
boiling  in  solutions  not  too  dilute  and  remaining  when  cold. 

Jc.  Stannic  chloride  blackens  when  warmed  with  glucose. — 
Nitrate  of  cobalt  in  concentrated  solution  of  glucose  is  not 
colored  by  addition  of  solid  potassa  and  boiling  (with  pure 
Sucrose  a  violet-blue  precipitate  is  obtained). 

Quantitative. — I.  Glucose  is  determined  in  its  reduction  of 
copper  by  use  of  a  standard  solution  made  as  follows  :  34.64 
grams  pure  crystallized  cupric  sulphate  dissolved  in  200  c.c. 


GL  UCOSE  :  LA  CTOSE.  171 

water,  with  150  grams  neutral  potassic  tartrate  in  about  500  c.c. 
of  a  10  per  cent,  solution  of  soda  (sp.  gr.  1.14),  the  mixture 
diluted  to  1  litre.  1  c.c.  is  reduced  by  0.005  gram  of  (anhy- 
drous) glucose,  or  by  0.0067  gram  of  lactose.*  The  solution 
must  not  suffer  change  by  boiling.  The  addition  of  about  100 
c.c.  of  pure  glycerin  (in  the  litre)  prevents  decomposition. 

The  solution  of  sugar  is  diluted  to  such  a  number  of  times  its 
own  volume  that  it  shall  not  be  far  from  1  per  cent,  glucose.  Then, 
10  c.c.  of  the  blue  solution  are  taken  in  an  evaporating-dish,  40 
or  50  c.c.  of  water  added,  and,  while  boiling,  the  graded  sugar 
solution  is  added,  until  no  blue  color  remains  (after  the  precipi- 
tate has  subsided  or  been  filtered  out).  The  quantity  of  sugar 
solution  used  contains  0.05  grams  glucose,  or  0.067  grams 
lactose. 

m.  Pure  sugar  may  be  determined  by  fermentation,  in  a 
Will's  Fresenius'  carbonic  acid  apparatus,  as  follows  :  In  the  first 
flask,  of  about  60  c.c.  capacity,  place  33.3  grams  of  the  solution 
to  be  determined,  and  which  is  made  of  5  to  10  per  cent,  strength 
of  sugar.  Add  0.3  gram  tartaric  acid  and  a  small  pinch  of  good 
pressed  yeast,  close  the  first  flask  (so  that  gas  must  pass  through 
sulphuric  acid  in  the  second  flask),  and  weigh  the  apparatus.  Set 
aside  at  30°  to  35°  C.  (86°  to  95°  F.)  for  three  days ;  and  weigh 
again.  The  weight  of  carbonic  anhydride  lost,  multiplied  with 
2.0454,  gives  the  amount  of  anhydrous  glucose,  or  of  crystallized 
lactose,  and,  if  multiplied  by  1.9432,  the  quantity  of  sucrose. 
The  results  are  not  close. 

188.  LACTOSE.  C6H12O6  (crystallized).  Milk  Sugar.— 
Characterized  by  its  physical  properties  (a) ;  its  reactions  as  a 
reducing  agent  (#),  and  with  acids  and  alkalies  (c) ;  with  am- 
moniacal  acetate  of  lead  and  with  lime  (d)  ;  and  by  its  fermenta- 


*  That  is,  180  parts  of  glucose  (C6  Hi2Oc ),  or  340  parts  of  lactose  $  of 
Ce  HizOe ),  suffice  to  consume  40  parts  of  oxygen  (2#O),  reducing  1347  parts 
(5  Cu  SOi  [Hs  O] )  of  copper  salt.  And  180  : 1347  :  :  5  :  34.64. 


172  CARBOHYDRATES. 

tions. — It  is  distinguished  from  Glucose  by  a  somewhat  weaker 
reducing  power  (£),  a  more  sparing  solubility  in  cold  water  or 
dilute  alcohol  (a),  and  by  blackening  with  sulphuric  acid  (c)  ; 
from  Sucrose  by  greater  reducing  power  (b)  and  insolubility  in 
strong  alcohol.  It  is  determined  volumetrically  by  the  potassio- 
cupric  solution  (see  Glucose,  I). 

a.  Lactose  crystallizes  in  hemihedral  trimetric  crystals,  hard 
and  colorless,  becoming  anhydrous   (CiaHoaOn)   at  ]50°  C.,  and 
turning   brown  without  melting  at  160°  C. — It  is  soluble  in  6 
parts  of  water  at  ordinary  temperature  or  2-J  parts  hot  water,  the 
cold  saturated  solution  having  a  maximum  spec.  grav.  1.060,  and 
is  insoluble  in  cold  absolute  alcohol  and  in  ether. 

b.  The  potassio  cupric  solution  is  reduced  by  lactose  very 
nearly  as  readily  as  by  Glucose  (187,  d  and  I)  (distinction  from 
Sucrose) ;  one-third  greater  quantity  being  required,  however,  to 
produce   the   same  effect. — Solution  of  cupric  acetate  is  only 
reduced  very  slightly  and  slowly  by  boiling  with  lactose   (dis- 
tinction from  Glucose). — Molybdate  of  ammonium  solution  is 
scarcely  changed  in  a  perceptible  degree  by  boiling  with  lactose 
(distinction  from  Glucose). — Ammoniacal  nitrate  of  silver  solu- 
tion is  reduced  by  boiling  with  lactose  (distinction  from  Sucrose). 

c.  Concentrated   sulphuric    acid    blackens    lactose,    rapidly 
when  warmed   (distinction  from  Glucose) . — Potassa  slowly  turns 
lactose  solution  brown  after  heating  to  boiling  point  (distinction 
from  Glucose). 

d.  Ammoniacal  acetate  of  lead  solution  gives  but  a  slight 
precipitate,  soluble  in  water  and  not  reprecipitated  on  boiling. 
With  milk  of  lime,   not  in  excess,  lactose  forms  a  compound 
soluble  in  water,  insoluble  in  alcohol. 

189.  SUCROSE.  C^H^Ojj.  Cane  Sugar.  Saccharose. — 
Characterized  by  its  physical  properties  (a) ;  its  reactions  as  a 
reducing  agent  (b) ;  its  reactions  with  alkalies  and  acids  (c),  and 
with  ammoniacal  acetate  of  lead  (d).  from  Glucose  it  is  dis- 
tinguished as  a  less  powerful  reducing  agent  (£),  by  blackening 
with  sulphuric  acid  or  turning  brown  with  potassa  solution  (c), 


SUCROSE.  173 

and  by  its  reaction  with  cobalt  (e).  It  is  distinguished  from 
Lactose  by  weaker  red.ucing  power  (b).  It  is  approximately 
separated  from  Lactose  by  solution  in  cold  water,  and  fully 
separated  from  Dextrin,  Gums,  Gelatin,  and  Albumenoids  by 
solution  in  90  per  cent,  alcohol.  It  is  separated  from  Fats, 
Resins,  etc.,  by  not  dissolving  in  (nearly  absolute)  ether.  It  is 
determined  by  volumetric  solution  of  potassio  copper  salt,  after 
being  changed  to  glucose  (c,  and  187,  Z),  by  the  specific  gravity 
of  its  pure  water  solutions,  by  its  specific  rotatory  power  as 
measured  in  the  polariscope,  and  by  fermentation  as  directed  for 
Glucose,  187,  m. 

a.  Sucrose  crystallizes  readily   in   monoclinic   (rhomboidal) 
prisms,  generally  with   hemihedral    faces,  and    anhydrous.     At 
160°  C.  (320°  F.)  it  melts  to  a  clear  liquid  which  solidifies  to 
"barley  sugar  " ;  at  about  210°  C.  (410°  F.)  Caramel  and  other 
products    are  formed. — Sucrose   is   soluble  in  about  ^  part  of 
water ;    scarcely  soluble  in  cold  absolute    alcohol,  insoluble  in 
ether,  chloroform,  benzole,  etc. — Sucrose  has  a  specific  rotatory 
power  of  73.8°  to  the  right. 

b.  Potassio  cupric  solution  is  at  first  not  at  all  reduced  by 
sucrose  on  warming,  or  even  on  digestion  over  the  water-bath, 
but  after  boiling  5  or  10  minutes,  a  slight  precipitate  of  cuprous 
hydrate  appears,  (distinction  from  Glucose,  Lactose,  and  Dextrin) . 
— Solution  of  acetate  of  copper  is  not  reduced  by  long  boiling 
(distinction  from  Glucose). — Ferricyanide  of  potassium  is  not 
reduced  to  ferrocyanide  by  hot  solution  of  sucrose   (distinction 
from  Glucose). — Stannic  chloride  is  reduced  on  warming,  and 
chromate  with  excess  of  potassa  on  boiling,  with  sucrose,  (reac- 
tions coinciding  with  those  of  Glucose  and  Lactose). — Ammonia- 
cal  nitrate   of  silver  solution  is  not  reduced,  though  turned  yel- 
lowish, on  warming  with  sucrose  (a  distinction  from  Glucose). 
Recent  oxide  of  silver  with  excess  of  potassa  is  blackened  on 
boiling  with  sucrose. — Molybdate  of  ammonium  (neutral  solution) 
is  unchanged  by  sucrose  (distinction  from  Glucose). 

c.  Sucrose  is  not  readily  colored  by  warming  with  solution 


174  CARBOHYDRATES. 

of  potassa  (distinction  from  Glucose).  Lime  forms  a  soluble 
compound  with  sucrose. — Concentrated  sulphuric  acid  blackens 
sucrose  on  warming,  with  separation  of  carbon  and  evolution  of 
sulphurous  and  formic  acids  (distinction  from  Glucose). — Dilute 
minreal  acids  (2  to -3  per  cent.),  boiled  10  to  15  minutes  with 
sucrose,  transform  it  into  glucose.  The  same  change  is  very 
slowly  effected  by  long  boiling  in  water,  and  with  moderate 
rapidity  by  boiling  with  dilute  vegetable  acids.  Also  by  the 
conditions  of  alcoholic  fermentation. 

d.  Ammoniacal  solution  of  acetate  of  lead  gives  a  white  pre- 
cipitate   (Pb2C12H18On),    scarcely    soluble   in  cold  but   readily 
soluble  in  hot  water. 

e.  The  blue  to  violet  and  rose-r.ed  precipitate  made  by  add- 
ing potassa  to  nitrate  of  cobalt  solution  and  boiling  is  scarcely 
altered  by  presence  of  sucrose,    or   held  a  little  more  in  the 
violet.      (In  presence  of  Glucose,  the  mixture  after  boiling  is 
colorless  or  brownish,  but  not  violet  or  blue.) 

CARAMEL.     A  mixture  of  three  compounds  : 
Caramelane — brittle  at  ordinary  temperatures,  soft  at  100°  C., 
odorless    and    bitter ;  deliquescent    and   very  soluble  in 
water,  sparingly  soluble  in  alcohol,  insoluble  in  ether. 
Caramelene — brittle,  freely  soluble  in  water,  not  deliquescent, 

sparingly  soluble  in  alcohol,  insoluble  in  ether. 
Caramelin — black,  shining,  and  infusible ;  having  three  modifi- 
cations with  different  and  varying  solubilities. 
Caramel  is  precipitated  by  subacetate  of  lead  solution  ;  and 
reduces  potassio  cupric  solution.     As  generally   prepared,   cara- 
mel has  a  characteristic,  "  burned-sugar  "  odor. 

190.  MANNITE.  C6H14O6.  Crystallizes  readily  from  solu- 
tion in  thin,  four-sided  prisms  ;  melts  at  160°  C.,  and  at  200°  C. 
(392°  F.)  distils  with  little  decomposition.  It  dissolves  in  6  or 
8  parts  of  water  of  ordinary  temperature,  in  80  parts  of  60  per 
cent,  alcohol  or  1400  parts  of  absolute  alcohol  or  smaller  quanti- 
ties of  boiling  alcohol,  but  is  insoluble  in  ether. — It  is  not  black- 


ALCOHOLS.  175 

ened  by  concentrated  sulphuric  acid,  or  turned  brown  by  boiling 
with  potassa,  and  it  does  not  reduce  the  potassio  cupric  sulphate 
solution.  It  is  not  subject  to  the  alcoholic  fermentation. 


ALCOHOLS   AND   THEIR   PRODUCTS. 

191.  METHYLIC  ALCOHOL.  CH4O.  Recognized  by 
its  sensible  and  physical  properties  (a) ;  its  reaction  with  potassa 
and,  as  a  commercial  article,  with  sulphuric  acid  (b) ;  by  solution 
of  recent  mercuric  oxide  (c) ;  by  its  reducing  power  (d),  and  its 
formation  of  formic  acid  (e).  It  is  separated  by  fractional  dis- 
tillation (f).  It  is  approximately  determined  as  methyl  oxalate 
(g)  or  as  formic  acid  (e,  and  Formic  acid  j  or  k) . 

a.  Pure  methylic  alcohol  is  a  colorless  liquid,  of  spec.  grav. 
0.800,  boiling  at  66°  C.  (151°  F.),  and  of  characteristic  taste  and 
odor.     The  commercial  article  is  seldom  free  from  empyreuma. 
It  is  miscible  in  all  proportions  of  water,  alcohol,  and  ether,  and 
dissolves   resins   and   nearly  all  substances   soluble   in   ethylic 
alcohol. 

b.  The  addition  of  potassa,  with  boiling  by  the  heat  of  the 
water-bath,  causes  a  brown  color  in  a  short  time  (Ethylic  alcohol 
only  after  a  long  time). — Ordinary  methylic  alcohol  gives  a  red 
to  red-brown  color  with  concentrated  sulphuric  acid. 

c.  Add  (to  the  distillate  /)  2  or  3  drops  of  very  dilute  solu- 
tion of  mercuric  chloride,  then  solution  of  potassa  in  excess, 
agitate  and  warm.     If  methylic  alcohol  is  present,  the  mercuric 
oxide  will  be  dissolved. 

d.  Methylic  alcohol  readily  decolorizes  permanganate   of 
potassium  solution ;  but  does  not  reduce  silver  nitrate,  or  potas- 
sio cupric  solution. 

e.  Oxidation  to  formic  acid  is  effected  by  distillation  of  2 


ALCOHOLS. 

c.c.  of  the  liquid  examined,  in  a  retort  of  60  c.c.  capacity,  with 
2  grams  of  powdered  bichromate,  15  c.c.  of  water,  and  25  drops 
of  sulphuric  acid — digesting  fifteen  minutes  and  then  distilling 
15  c.c. 

f.  In  the  distillation  of  methylic  alcohol,  add  a  little  animal 
charcoal  and  a  little  solution  of  sodic  carbonate,  and  receive  the 
distillate  at  66°  to  76°  C.  (151°  to  169°  F.) 

Quantitative. — g.  Place  in  a  retort  55  grams  crystallized 
oxalic  acid  and  the  mixture  of  35  grams  of  concentrated  sul- 
phuric acid  and  25  grams  of  distillate  f,  digest  for  ten  hours,  and 
distil  from  an  oil-bath  at  160°  to  180°  C.,  as  long  as  anything 
passes  over.  The  distillate  consists  of  oxalic  ethers ;  methyl 
oxalate  being  freely  soluble  in  water,  while  ethyl  oxalate  is 
nearly  insoluble.  The  distillate  is  now  washed  with  25  times 
its  volume  of  w'ater ;  the  clear  solution  decanted,  digested,  in  a 
close  bottle,  with  excess  of  potassa,  the  mixture  acidulated  with 
acetic  acid  and  precipitated  with  calcium  chloride  (adding  potassic 
acetate).  Gather  the  oxalate  of  calcium,  wash,  dry,  and  ignite 
to  carbonate  (adding  ammonium  carbonate  and  igniting  slightly 
again,  if  necessary),  CaCO3  ;  2CH4O  ;  ;  1  :  0.64. 

192.  ETHYLIC  ALCOHOL.  C2H6O.  Characterized  by 
its  physical  and  sensible  properties  (a)  ;  by  the  extent  of  its 
reducing  power  (b)  ;  by  its  formation  of  iodoform  (c)  ;  of  various 
compound  ethers  (df),  and  of  acetic  acid  (e). — Separated  by 
fractional  distillation,  solubility  in  water,  and  insolubility  in 
fixed  oils.  Separated  from  methylic  alcohol  as  an  oxalic  ether 
(191,  g),  from  amylic  alcohol  by  solution  in  water  or  by  frac- 
tional distillation. — Determined  by  the  specific  gravity  or  by  the 
boiling  point  of  its  mixtures  with  water. 

a.  A  transparent,  limpid  liquid,  of  spec.  grav.  0.794,  freezing 
at  -95°  C.  and  boiling  at  78°  C.  (173°  F.),  of  an  agreeable  and 
pungent  odor  and  a  sharp  and  burning  taste.  It  is  miscible  writh 
water,  ether,  chloroform,  benzole,  petroleum  naphtha,  volatile 
oils  and  castor  oil,  and  dissolves  resins  and  camphors. 


ETHYLIC   ALCOHOL.  177 

b.  Alcohol  —  as  a   hot   liquid   or   as   vapor  —  slowly  reduces 
chromic  acid,  or  a  mixture  of  potassic  bichromate  and  sulphuric 
acid  —  the  alcohol  being  first  oxidized  to  acetic  acid.     (This  is  in 
common   with   aldehyde,    acetic    acid,    formic   acid,   and   many 
volatile   organic  bodies.)     Permanganate  of  potassium  is  but 
slowly  reduced  by  ethylic  alcohol  —  so  that  the  red  tinge  of  a 
slight  addition  of  a  y^Vo"  solution  is  scarcely  at  all  affected  for 
several    minutes.      (Methylic   alcohol,  Formic  acid,    Aldehyde^ 
and  many  other  volatile  organic  bodies,  more  readily  reduce  the 
permanganate.) 

c.  The  production  of  iodoform  from  alcohol  is  a  result  (in 
part)  of  the  reducing  power  of  the  latter  upon  alkaline  iodate  : 

6KHO+6I=5KI+KIO3+3H2O 


Take  3  to  5  c.c.  of  the  distillate  to  be  tested,  5  to  6  drops  of  a 
10  per  cent,  potassa  solution  ;  warm  to  100°  or  120°  C.  (212°  to 
248°  F.),  and  add  —  of  a  solution  of  potassic  iodide  in  five  parts 
of  water,  saturated  with  iodine  —  until  the  liquid  is  brownish- 
yellow.  If,  on  agitation,  the  color  does  not  disappear,  add  one 
or  two  drops  of  the  potassa  solution.  If  alcohol  is  present,  the 
iodoform  appears,  sooner  or  later,  in  yellow  scaly  particles. 
With  a  power  of  200  to  400  diameters,  these  are  seen  as  hexa- 
gonal stars  and  rosettes.  Iodoform  is  formed  also  by  Aceton, 
Aldehyde,  Acetic  ether,  Butyric  alcohol,  Arnylene.  Not  formed 
by  Ether,  Amylic  Alcohol,  Chloroform,  Chloral,  Chloral  Hydrate, 
and,  according  to  LIEBEN,  not  formed  by  Methylic  alcohol. 

d.  See  under  Acetic  acid,   40,  b,   and   Butyric  acid,  41,   b. 
(One  c.c.  of  the   distillate  to  be  tested  is  treated  with  0.3  to  0.5 
gram  of  dry  potassic  acetate  and  2  or  3  c.c.  of  sulphuric  acid.) 

e.  Acetic  acid   is  formed  from  alcohol  by  digestion  with  a 
mixture  of  bichromate  of  potassium  and  dilute  sulphuric  acid,  or 
of  permanganate  of  potassium  and  dilute  sulphuric  acid.     See  40. 

193.  ALDEHYDE.     C2H4O.     Acetic  Aldehyde.  —  A  trans- 


178  ALCOHOLIC  PRODUCTS. 

parent  and  colorless  liquid,  of  spec.  grav.  0.800  at  0°  C.,  distill- 
ing at  about  21°  C.  (70°  F.),  neutral  in  reaction,  of  a  pungent 
and  suffocating  odor,  slightly  resembling  that  of  apples.  The 
vapor  irritates  the  eyes. — It  is  miscible  in  all  proportions  with 
water,  alcohol,  and  ether,  but  not  with  aqueous  chloride  of  cal- 
cium (separation  from  Alcohol).  It  dissolves  sulphur,  phos- 
phorus, and  iodine. — It  promptly  reduces  ammonio  nitrate  of 
silver,  forming  a  specular  coating  on  the  glass  (distinction  from 
Acetic  acid,  Alcohol,  Ether).  It  burns  readily,  with  a  blue 
flame.  It  is  blackened  by  sulphuric  acid. — Potassa  solution, 
warmed  with  aldehyde,  colors  it  brown,  with  deposition  of  "  alde- 
hyde resin  "  and  formation  of  acetate  and  formate  (a  character- 
istic test).  Ammonia  (gas)  with  aldehyde  forms  aldehyldate  of 
ammonium,  a  compound  of  an  ammoniacal,  terebinthinate  odor, 
crystallizing  (from  ether  or  alcoholic  ether)  in  transparent  acute 
rhombohedrons.  melting  between  70°  and  80°  C.,  and  distilling 
at  100°  C.  It  dissolves  in  water,  sparingly  in  alcohol  and  ether. 
With  other  bases  aldehyde  acts  as  a  monobasic  acid,  exchanging 
one  atom  of  its  hydrogen. 

194.  SULPHETHYLATES.  HC2H6SO4.  Ethyl-sulphates. 
— Sulphethylic  acid  is  a  limpid,  oily,  acid  liquid,  of  spec.  grav. 
1.315,  decomposed  by  heat,  evolving  ether  at  130°  to  140°  C. 
(266°  to  284°  F.) — It  is  soluble  in  water  and  alcohol,  not  in 
ether. — Its  metallic  salts  are  all  soluble  in  water,  and  are  mostly 
soluble  in  aqueous  but  not  in  absolute  alcohol,  the  ammonium 
salt  only  is  soluble  in  ether.  The  sulphethylates  are  gradually 
decomposed  in  boiling  water.  Barium  sulphethylate  crystal- 
lizes in  permanent  monoclinic  prisms,  with  2H3O  which  is  ex- 
pelled in  a  vacuum,  the  anhydrous  salt  bearing  100°  C.  without 
change.  It  dissolves  in  about  one  part  of  water,  and  in  a  larger 
quantity  of  aqueous  alcohol.  The  sodium  salt  crystallizes  in 
slightly  efflorescent  hexagonal  plates,  with  H2O,  soluble  in  less 
than  one  part  of  water,  melting  at  86°  C.  When  anhydrous,  it 
bears  100°  C.  without  change. 


ETHER.  179 

195.  ETHER.  (C2H5)2O.  Recognized  by  its  sensible  and 
physical  properties  (a).  Separated  by  distillation,  or  by  solu- 
tion (b). 

a.  Spec,  grav.,  at  15°  C.,  0.713;  at  17.5°  C.,  0.7185.  Boil- 
ing  point,  35°  C.  (95°  F.)  Ether  of  spec.  grav.  0.728,  .and 
boiling  at  blood  heat,  has  from  5  to  6  per  cent,  of  about  90  per 
cent,  alcohol ;  that  of  spec.  grav.  0.750  has  about  25  per  cent, 
of  88  per  cent,  alcohol.— At  17.5°  C.  (63.5°  F.),  one  part  of 
ether  dissolves  in  12  parts  of  water,  and  35  parts  of  ether  dis- 
solve one  part  of  water.  Alcoholic  ether  is  more  soluble  in 
water  : 

"  Ether  "  of  sp.  gr.  0.719  to  0.721  dissolves  in  12.0  parts  water. 

"  "  "  0.724  "  0.726  "  "  10.0  "  " 

"  "  "  0.729  "  0.731  "  "  7.7  "  " 

"  "  "  0.733  "  0.735  "  "  6.2  "  " 

"  "  "  0.738  "  0.741  «  "  5.0  "  " 

«  «  u  0.743  "  0.746  "  "  4.3  "  " 

"  "  «  0.748  "  0.750  "  «  3.8  "  " 

Salts  not  soluble  in  ether  (as  dry  potassiu  carbonate)  separate 
it  from  water  almost  wholly.  Ether  is  miscible  in  all  propor- 
tions witk  alcohol,  chloroform,  benzole,  petroleum  naphtha,  fixed 
and  volatile  oils,  and  dissolves  resins,  iwlphur,  phosphorus, 
iodine,  and  ferric,  mercuric,  and  auric  chlorides.  Tannic  acid 
d^es  not  dissolve  or  deliquesce  in  absolute  ether,  but  deliquesces 
ir.  the  "stronger  ether"  of  spec,  grav.  0.728.  Ether  is  less 
Soluble  in  glycerin  than  in  water,  It  mixes  with  concentrated 
sulphuric  acid,  the  liquid  turning  brown  when  warmed. — In  the 
air,  ether  very  slowly  oxidize*  to  acetic  acid.  Its  combustibility 
renders  it  necessary  K>  use  strict  precautions  in  the  manipulation 
tf  its  vapor. 

5.  Ether  is  p^prox;mately  separated  from  alcohol  by  means 
of  glycerin  (or  water).  A  test-tube  of  over  20  c.c.  capacity  is 
from  the  point  of  10  c.c.  contents  (marked  0)  to  the 
r/  40  c.c.  contents  (marked  10).  Ten  c.c.  of  glycerin  or 


180  ALCOHOLIC  PRODUCTS. 

water  is  taken  in  the  tube,  then  10  c.c.  of  the  ether  is  added,  the 
contents  shaken  together,  the  ether  allowed  to  separate,  and  the 
increase  in  the  lower  layer  is  read  off. 

196.  NITROUS  ETHER.     C2H5NO2.     Nitrite  of  ethyl.— 
Characterized  by  its  sensible  and  physical  properties  (a)  and  by 
reactions  of  nitrites. — Estimated,  in  its  alcoholic  mixtures,  by 
their  boiling  point  (6),  and  by  volumetric  trial  with  permangan- 
ate (c). 

a.  Nitrite  of  ethyl  is  a  yellowish  liquid,  of  spec.  grav.  0.947, 
boiling  at  16.6°  (62°  F.),  and  of  an  agreeable  odor  of  apples.     It 
is  soluble  in  48  parts  of  water,  in  all  proportions  of  alcohol,  and 
freely  soluble  in  dilute  alcohol.     It  gradually  decomposes ;  more 
quickly  in  contact  with  water. 

b.  "  Spirit  of  nitrous  ether,"  of  5  per  cent,  nitrite  of  ethyl, 
boils  at  63°  C.  (145°  F.)  :  the  test-tube  containing  it  being  im- 
mersed in  water  of  that  temperature,  and  a  few  fragments  of 
broken  glass  added. 

Quantitative. — c.  10  grams  of  the  spirit  of  nitrous  ether  are 
macerated,  with  1.2  to  1.5  grams  of  fused  potassa,  in  a  stoppered 
flask,  for  12  hours,  occasionally  agitating.  Then  pour  the  mixture 
into  a  beaker,  dilute  with  an  equal  bulk  of  water,  and  leave  at  a 
warm  temperature  till  the  odor  of  alcohol  disappears.  Acidulate 
slightly  with  sulphuric  acid,  and  add,  from  a  burette,  a  solution 
of  potassium  permanganate  of  known  strength,  until  the  color 
ceases  to  be  discharged.  The  number  of  grams  of  permanganate 
expended,  multiplied  by  1.18,  equals  the  number  of  grams  of 
ethyl  nitrite  in  the  10  grams  of  material  taken. 

197.  CHLOROFORM.     CHC13.     Identified  by  its  sensible 
and  physical  properties  (a) ;  its  liberation  of  chlorine  when  de- 
composed (£>),  and  its  production  of  isonitril  (c).     It  acts  as  a 
reducing  agent  (d).     It  is  separated  by  washing  with  concentrated 
sulphuric  acid  and  with  water,  and  rectification  from  alkaline 
carbonate,  lime,  calcium  chloride,  animal  charcoal   (e).     It  may 


CHLOROFORM.  181 

he   estimated  from   the   chloride  it  gives  after  digestion  with 
alcoholic  fixed  alkalies. 

a.  Chloroform  is  a  colorless  liquid,  of  spec.  grav.  1.497  (at 
15°  C.),  boiling  at  61°  C.  (142°  F.).     It  is  neutral  in  reaction, 
and  has  an  agreeable  sweet  ethereal  odor   and  burning  sweet 
taste.     It  is  not  readily  combustible,  but  burns  with  paper,  with 
a  green-bordered  flame.     By  standing,  especially  in  the  light  and 
if  free  from  alcohol,  it  becomes  acid  and  gives  reactions   for 
chlorine   and   hydrochloric   acid.  —  Chloroform    is   not    miscible 
in  water  except  in  traces,  but  is  soluble  in  all  proportions  of 
alcohol,  ether,  benzole,  petroleum  naphtha,  bisulphide  of  carbon, 
fixed  and  volatile  oils  —  not  in  concentrated  sulphuric  acid.     It 
dissolves    sulphur,  phosphorus,  iodine,   iodoform,  resins,   caout- 
chouc, and  gutta  percha. 

b.  Chloroform  is  decomposed,  with   production   of  chlorine 
and  hydrochloric  acid,  when  it  is  passed  in  vapor  through  a  red- 
hot  tube  ;  or,  with  production  of  chloride  and  formate,  when 
digested  with  alcoholic  solution  of  potassa  (slowly  by  aqueous 
potassa).     (Alcoholic  ammonia  produces  ammonium  cyanide  and 
chloride  —  the  better  with  help  of  potassa.) 

CH  C134-4KH  0=3K  Cl-j-K  CH  O2+2H8O 
CH  C15N  H    =3NHCl]Sr  H  C  N 


Also,  with  production  of  hydrochloric  acid,  by  nascent  hydrogen, 
as  evolved  by  zinc  with  sulphuric  acid  diluted  with  alcohol.  — 
The  free  chlorine  is  made  evident  by  potassic  iodide  (and  starch), 
and  the  hydrochloric  acid  by  silver  salt.  (Neither  pure  nor  alco- 
holic chloroform  affects  silver  nitrate.) 

c.  Chloroform,  even  in  solution  with  5,000  parts  of  alcohol, 
when  treated  with  anilin  (or  other  monamine)  and  then  with 
alcoholic  soda,  forms  an  isonitril,  recognized  by  its  characteris- 
tic odor  (HOFFMANN).  This  test  distinguishes  chloroform  from 
Chlorcethylidene  (C2H4C12)  .  Iodoform,  Bromoform,  Chloral,  etc., 
react  in  the  test,  the  same  as  chloroform. 


182  ALCOHOLIC  PRODUCTS. 

d.  Chloroform  readily  reduces  the  hot  potassio  cupric  solu- 
tion (distinction  from  chlorcethylidene  and  from  alcohol) . 

e.  Chloroform   may  be  separated  from   slight   mixtures    of 
Ether,  Alcohol,  water,  etc.,  as  follows  :  To  10  parts  of  the  impure 
chloroform,  add  2  parts  of  concentrated  sulphuric  acid,  and  shake 
together  occasionally  for  24  hours.     Remove  the  upper  layer, 
add  to  it  -|  part  of  (crystallized)  carbonate  of  sodium  previously 
dissolved  in  1  part  of  water,  agitate  and  digest  (cold)  for  half  an 
hour,  then  remove  the  lower  layer  and  distil  it  from  -gL  part  of 
freshly-burned  lime. — Distillation    from    dry  calcium    chloride 
separates    chloroform    from    alcohol. — To    separate  from  Ethe- 
real   Oil    (ethyl   and   ethylene   sulphates),    distil   from   animal 
charcoal. 

198.  CHLORAL  HYDRATE.  C2HC13O.H2O.  Charac- 
terized by  its  sensible  and  physical  properties  (a),  and  its  forma- 
tion of  chloroform  (5),  and  of  chloralide  (c).  It  has,  with  alkalies, 
considerable  reducing  power  (d).  Separated  from  chloral  alco- 
holate  by  its  slight  solubility  in  cold  chloroform  and  its  greater 
solubility  in  cold  water. — Estimated  from  the  amount  of  chloro- 
form it  produces  (e). 

a.  A  friable  solid,  crystallizing  from  solvents  in  transparent 
rhomboidal  crystals,  or  congealing  in  a  white  crystalline  mass, 
melting  at  about  60°  C.  (140°  F.)  and  boiling  at  95°  C.  (203°  F.) 
• — (the  Alcoholate  boils  at  116°  C.).  It  slowly  sublimes,  in  the 
bottle,  at  ordinary  temperatures.  It  is  neutral  in  reaction,  and 
of  an  aromatic,  penetrating,  and  slightly  acrid  odor,  and  bitter, 
caustic  taste.  Melted  in  a  spoon,  over  the  flame,  it  does  not  take 
fire  (distinction  from  the  alcoholate). — It  is  slightly  deliquescent, 
readily  soluble  in  1J  parts  of  water  (the  alcoholate  dissolves 
sparingly  in  cold  water)  ;  soluble  in  alcohol,  ether,  benzole, 
petroleum  naphtha,  bisulphide  of  carbon  ;  slightly  soluble  in  cold 
chloroform  (the  alcoholate  freely  soluble).  It  forms  liquid  mix- 
tures with  camphor,  and  with  phenic  acid,  and  a  crystalline 
mixture  with  glycerin. 


CHLORAL   HYDRATE.  183 

b.  Fixed  and  volatile  alkalies,  and  their  carbonates,  in  solu- 
tion, decompose  chloral  hydrate — the  chloroform  subsiding  from 
the  milky  mixture'. 

C2HC13O.H20+KHO=CHC13+K:CH02+H20 

(100  parts  chloral  hydrate  producing  72.2  parts  of  chloroform.) 
(Trichloracetic  acid,  also  decomposed  by  alkalies  into  chloroform 
and  formate,  has  an  acid  reaction,  and  boils  at  195°  C.) 

c.  Concentrated    sulphuric    acid   separates,    from    about   an 
equal  weight  of  chloral  hydrate,  anhydrous  chloral — the  latter 
rising  to  the  surface,  as  a  pungent  and  irritating  oily  liquid,  of 
spec.  grav.  1.5. — Chloralide  is  formed  when  chloral  hydrate  (con- 
centrated, if  necessary,  by  distillation  from  chloride  of  calcium) 
is  heated  with  about  six  times  its  volume  of  concentrated  sulphuric 
acid,   at  125°  C.,  for  some  time.     When   cool,  the   mixture   is 
diluted  with   six  measures  of  water,  and,  if  carbonized   at  all, 
extracted  with  ether.     On  evaporating  the  ether  the  chloralide 
(C5H2C16O3)   crystallizes    in   stellate   groups  .of  prisms    (or   in 
needles)     which    melt    at    116°  C.   and   burn  at  200°   C.  with 
a    green-edged   flame. — In    certain    conditions,    sulphuric    acid 
changes    chloral  into  metachloral   (insoluble  in  water,  alcohol, 
or  ether). 

d.  Chloral  hydrate,  in  the  act  of  decomposition  by  ammonia, 
promptly   reduces   nitrate   of  silver  as  a  specular   coating. — 
Aqueous  solution  of  pure  chloral  hydrate  does  not  within  a  few 
minutes  perceptibly  decolorize  the  permanganate  of  potassium 
solution,  and  does  not  at  all  affect  argentic  nitrate. — The  potassio 
cupric  solution  is  reduced  by  chloral  according  to  197,  d.     ' 

Quantitative. — e.  Take  10  grams  of  the  chloral  hydrate, 
dissolve  in  the  least  quantity  of  water,  and  add,  in  a  graduated 
tube  holding  20  c.c.,  ammonia  enough  to  be  a  slight  excess  for 
the  absolute  chloral  hydrate  taken,  according  to  the  equation  in  b 
(5  c.c.  of  water  of  ammonia  of  spec.  grav.  0.90).  Stopper  tightly 
in  the  tube,  which  should  be  nearly  filled  by  the  liquid,  and  leave 
until  the  subsident  layer  no  longer  increases — four  to  twelve 


184  ALCOHOLIC  PRODUCTS. 

hours.  The  c.c.  of  chloroform  are  multiplied  by  1.5  for  grams. 
Closer  results  are  obtained  by  taking  50  grams  chloral  hydrate. 

199.  IODOFORM.     CHI3.     A  sulphur-yellow  solid,  crys- 
tallizing in  hexagonal  plates,  stars,  and  rosettes;  melting,  at  115° 
to  120°  C.,  with  partial  vaporization  and  partial  decomposition 
into  carbon,  hydriodic  acid,  and  iodine.     It  has   a  saffron-like 
odor,  reminding  of  chloroform  and  of  iodine,  and  a  taste  like  the 
same  substances,  becoming  unpleasantly  strong  of  iodine. — It  is 
soluble  in  13,000  parts  of  water  (to  which   it  imparts   a  slight 
odor  and  taste),  in  80  parts  of  cold  or  12  parts  of  boiling  alcohol 
of  80  per  cent.,  in  20  parts  of  ether,  and  soluble  in  chloroform, 
bisulphide    of  carbon,   fixed    and   volatile    oils.     The    alcoholic 
solution  is  straw-yellow ;  the  ether  solution,  gold-yellow ;  both 
solutions  are  neutral,  and  have  a  sweet-ethereal,  burning  taste  and 
iodine-like  after-taste. — It  is  difficultly  and  imperfectly  decom- 
posed by   boiling  aqueous  potassa,  but  (WITTSTEIN)    alcoholic 
potassa  decomposes  it,  forming  iodide  and  formate  (see  chloro- 
form, b). 

200.  CROTON-CHLORAL  HYDRATE.    C4H3C13O.    The 

trichlorinated  aldehyde  of  crotonic  acid. — Thin,  dazzling-white 
plates,  melting  at  78°  C.,  volatile  in  steam  at  100°  C.,  boiling  at 
163°.  It  has  a  sweetish,  melon-like  taste,  and  its  vapor  irritates 
the  eyes.  It  is  sparingly  soluble  in  cold,  freely  in  hot  water,  and 
soluble  in  alcohol  and  in  glycerin.  Potassa  decomposes  it  with 
formation  of  potassic  chloride  and  formate  and  dichlorallylene 
(C3H2C12). 

201.  AMYLIC   ALCOHOL.     C5H12O.     Characterized  by 
its  sensible  and  physical  properties  (a)  ;  by  its  production  of  red 
sulphamylic  acid  (b) ;  by  its  formation  of  odorous  ethers  (c). — It 
is  separated  from  alcohol  by  fractional  evaporation  or  distilla- 
tion, or  by  adding  water  and  extracting  with  ether  (d) ;  from 
water,  in  the  slight  proportions  miscible,  by  adding  petroleum 
naphtha  or  benzole,  or  \iy  adding  common  salt  (e). 


AMYLIC  ALCOHOL.  185 

a.  A  colorless  and  transparent  liquid)  of  spec,  grav.  0.816, 
boiling  at  132-3°  C.  (270°  F.),  and  having  a  sharp  taste  and  a 
characteristic,  pungent  odor.     Its  vapor  excites   coughing,  a  few 
moments  after  it  is  inhaled. — It  is  soluble  in  about  40  parts  of 
water,  less  soluble  in  solution  of  common  salt,  soluble  in  all  pro- 
portions of  alcohol,  ether,  chloroform,  benzole,  petroleum  naph- 
tha, fixed  and  volatile  oils.     It  makes  a  slowly  evanescent  oil-spot 
upon  paper. — It  burns  with  a  smoky  flame. 

b.  When  two  parts  of  amylic  alcohol  are  digested  warm  with 
three  parts  of  concentrated  sulphuric  acid,  sulphamylic  acid,  or 
amyl  sulphuric  acid  is  formed — having  a  red  color  and  dissolving 
freely  in  water. 

c.  Distilled   or   digested    hot   with    concentrated    sulphuric 
acid  and  potassic  acetate,  the   odor  of  "  pear-oil  "  is  developed 
— from  formation  of  amyl  acetate. — Distilled  or  digested  with 
sulphuric  acid  and  a  little  water  and  bichromate  of  potassium, 
the  apple-odor  of  valeric  aldehyde  is  first  generated,  and  then  the 
peculiar  odor  of  valeric  acid  (42). 

d.  It  is  separated  from  (aqueous)  ethylic  alcohol,  by  adding  an 
equal  volume  of  pure  ether,  and    then  to  the  whole  an  equal 
volume  (or  enough)  water  to  cause  the  ether  to  separate.     The 
latter  will  contain  most  of  the  amylic  alcohol.     Benzole  or  petro- 
leum naphtha  may  be  used  instead  of  ether. 

e.  If  from   100  c.c.  of  commercial    "fusel-oil"    are    slowly 
distilled  5  c.c.,  and  this  be  agitated  with  a  saturated  solution  of 
common  salt,  the  separation  of  an  oil-layer  of  2.5  c.c.  or  over 
indicates  that  there  is  less  than  15  per  cent,  of"  proof  spirit"  in 
the  fusel-oil. taken. 

202.  "  FUSEL-OIL  "  contains,  besides  amylic  alcohol,  small 
proportions  of  Butyric,  Valeric,  and  volatile  Fatty  Acids,  and  of 
propylic  and  butyric  alcohols. — In  examination  of  spirits  for 
fusel-oil,  add  2  or  3  c.c.  of  potassa  solution,  to  about  30  c.c. 
of  the  material,  and  evaporate  by  a  gentle  heat  to  dryness. 
Add  5  or  6  c.c.  of  sulphuric  acid  and  nearly  as  much  water : 


186  ALCOHOLIC  PRODUCTS. 

when,  if  the  acids  in  question   are   present,  their    odor  will  be 
apparent.* 

203.  NITRITE  OP  AMYL.  C6HnNO2.  A  light-yellow- 
ish liquid,  darkening  when  heated,  of  spec.  grav.  0.877,  boiling  at 
about  96°  C.  Its  vapor  has  a  reddish-yellow  color.  Its  odor 
resembles  that  of  ethyl  nitrite. — Sulphuric  acid  (concentrated) 
decomposes  it  with  explosive  violence,  sometimes  with  combus- 
tion. Alcoholic  potassa  decomposes  it  quickly,  forming  potassic 
nitrite :  aqueous  potassa  decomposes  it  slowly. 

*  Farther,  see  Prescott's  Examination  of  Alcoholic  liquors,  New 
York,  1875. 


INDEX. 


ABSINTHIN,  151, 156. 

Acacia,  162. 

Acetic  Acid,  13,  58. 

Acetic  Ether,  formation  of,  59. 

Acids,  13. 

Separated  as  lead  salts,  59. 
Aconitia,  125,  128,  135, 137  to  140, 142 

to  144,  148,  150. 
Aconitic  Acid,  13,  21. 
Acrolein,  formation  of,  86. 
Acrylic  Acid,  formation  of,  86. 
Agaric  Resin,  separated  from  Gam- 
boge, 98. 

Separated  by  Chloroform,  104. 
Albumen,  158. 
Albumenoids,  13,  157. 
Alcohol,  13,  176. 
Alcohols,  175. 
Aldehyd,  13,  177. 
Aldehyds,  as  Volatile  Oils,  104. 
Alkaloids,  Fixed,  13. 

Volatile,  13,  120. 
AUspice  Oil— See  Pimento  Oil. 
Almond  Oil,  73,  76,  78,  81. 
Almonds,  Oil  of  Bitter— See  Bitter 

Almond  Oil. 
Aloes  Resins,  93,  103. 

Separation  of  Gamboge  from,  98. 
Aloin,  151,  156. 
Amber,  93,  103. 

Amber  Oil,  107,  108,  109,  111,  114. 
Ammonia,  124. 
Ammoniac,  93,  103. 
Amygdalin,  144,  152. 
Amylic  Alcohol,  13,  184. 
Amyl,  Mtrite  of,  186. 
Amyloid,  168. 
Anilin,  120, 140,  142,  146,  148. 

Compounds,  13,  14. 
Anise  Oil,  107  to  111,  114. 
Anthracene,  13,  117. 
Arabic  Acid,  162. 
Arabin,  162. 
Asparagin,  153,  156. 
Assaf  etida,  94,  103. 
Atropia,  125,  128,  135,  137  to  140,  142 

to  144,  147,  148,  150. 
Auric  Chloride,  as  Reagent  for  Al- 
kaloids, 150. 

BALM  Oil,  107, 112. 
Balsams,  93. 


Balsam  of  Copaiba,  96. 

Peru,  102,  103. 

Tolu,  103. 
Baranilin,  120. 
Bases,  Volatile,  120. 
Beech-nut  Oil,  73,  76,  81. 
Benzene,  119. 
Benzoin,  94,  103. 
Benzole,  13,  118. 

Benzoyl    Hydride— see    Bitter    Al- 
mond Oil. 
Berberina,  125,  128,  135  to  138,  140, 

142,  143,  145,  147,  149,  151. 
BergamotOil,  107  to  110,  112,  114. 
Bitter  Almond  Oil,  107  to  111. 

Artificial — see  Nitrobenzole. 

Formation  of,  62. 
Boheic  Acid,  13,  36. 
Bone  OiL  76,  81. 
British  Gum — see  Dextrin. 
Bromated  Camphor,  116. 
Brucia,  125,  128,  135,  137  to  140,  142, 

143,  145  to  150. 
Butter,  74,  81. 
Butyric  Acid,  13,  60,  61. 

Ether,  Formation  of ,  62. 
Butyrin  in  Butter,  81. 

CACAO  Butter,  74. 
Cacodyl,  Formation  of,  59. 
Caffeina,  125,  127,  128,  135  to  140,  143 

to  145,  148  to  150. 
Caffetannic  Acid,  13,  28,  35. 
Cajeput  Oil,  107  to  110,  112, 114. 
Calamus  Oil,  107  to  110. 
Calvert's  Tests  for  Fixed  Oils,  78. 
Camphor  Oil,  107. 
Camphors,  13,  116. 
CanaubaWax,  95,  103. 
Cane  Sugar— see  Sucrose. 
Cannabin,  98. 
Caoutchouc,  95,  103. 
Capric  Acid,  67,  68. 
Caproic  Acid,  67,  68. 
Caprylic  Acid,  67. 
Caramel,  173,  174. 
Caramelane,  174. 
Caramelene,  174. 
Caramelin,  174. 

Caraway.  Oil  of,  107  to  110,  112. 
Carbazotic    Acid— see    Nitrophenic 

Acid. 


187 


188 


INDEX. 


Carbohydrates,  13,  161. 
Carbolic  Acid — see  Phenic  Acid. 
Carbon,  uncombined,  11. 

Compounds  of,  111. 
Cardamon  Oil,  107,  108. 
Carminic  Acid,  13,  40. 
Carmine — see  Carminic  Acid. 
Cascarilla  Oil,  107,  109,  112. 
Casein,  159. 

Castor  Oil,  73,  76,  78,  80,  81. 
Catechu,  34. 

Catechuic  Acid,  13,  28,  34. 
Catechutannic  Acid,  13,  28,  33. 
Cathartic  Acid,  153,  156. 
Cathartin — sea  Cathartic  Acid. 
Cellulose,  13,  167. 
Cephselic  Acid,  28. 
Ceroso-ceric  oxide,  as  Reagent,  146. 
Cerotic  Acid,  13,  70. 
Chamomile  Oil,  107,  108,  109. 
Chloral  Hydrate,  13,  182. 

with  Oil  of  Peppermint,  115. 
Chloralide,  182. 
Chlorine,  as  Reagent  for  Alkaloids, 

148. 

Chloroform,  13,  180. 
Chrysammic  Acid,  152. 
Chrysophanic  Acid,  13,  41. 
Chrysophane  —  see     Chrysophanic 

Acid. 
Cinchona  Bark,  separation  of  Acids 

from,  37,  39. 
Cinchonia,  125,  128.  136  to  140,  142, 

143,  145,  149,  150. 
Cinchonidia,  125, 128,  149,  150. 
Cinchotannic  Acid — see  Quinotannic 

Acid. 

Cinnamate  of  Cinnyl,  102. 
Cinnamon  Oil,  107  to  110,  112,  114. 
Citric  Acid,  13,  18. 
Citric  Acid,  distinguished  from  Tar- 

taric,  15. 

Cloves,  Oil  of,  107  to  111. 
Cochineal,   separation    of  Carminic 

Acid  from,  26. 
Cocoa-nut  (Coco-nut)  OH,  80. 
Codeina,  125,  127,  128,  136  to  138,  140 

to  143, 145,  147  to  150. 
Cod-liver  Oil,  73,  77,  78,  80,  81. 
Coffee,    separation   of    Caffetannic 

Acid  from,  35. 

Cohesion-figures  of  Oils,  74,  105. 
Colchicia  (Colchicin),   125,  127,  128, 

135  to  140,  142  to  150. 
Colocynth,  separation    from  Gam- 
boge, 98. 

Colocynthin,  136,  137,  145. 
Colombic  Acid — see  Columbia  Acid. 
Colombin,  145,  151,  156. 


Colombo  Bitter— see  Colombin. 
Colopholic  Acid,  96. 
Colophony,  95,  103. 

Separation  from  Lac,  101. 
Color  Resins,  93. 
Columbic  Acid,  13,  39. 
Columbo  Root,  separation  of  Acid 

from,  39. 
Colza  Oil,  73. 
Conia,  123,  128,  135  to  138, 140, 142  to 

145,  149. 

Convolvulic  Acid,  100. 
Convolvulin,  100, 103. 

Separation  from  Gamboge,  98. 
Convolvulinol,  100. 
Convolvulinolic  Acid,  100. 
Copaiba  Oil,  107,  lOa  110,  113,  114. 
Copaiba  Resins  and  Balsam,  96. 
Copaivic  Acid,  96. 
Copal,  96,  103. 
Coriander  Oil,  107,  113. 
Cotton-seed  Oil,  73,  76,  81. 
Creosol,  68. 
Creosote,  13,  116. 
Cresylic  Acid,  separation  of  Phenic 

from,  48,  50. 
Croton  Chloral  Hydrate,  184. 

Oil,  73,  77. 

Cubebin,  135  to  138,  145,  154,  156. 
Cubeb  Oil,  107  to  110. 
Cumidin,  120. 
Cummin  Oil,  107,  108. 
Curarin,  136,  137,  142,  145,  146, 147. 
Cymidin,  120. 
Cytisin,  142. 

DAMMARA  (Dammaran,  etc.),  96, 103. 

Daphnin,  125,  128,  148. 

Daturia — see  Atropia. 

Delphina,  125,  128,  135  to  138,  141  to 

145,  149, 150. 
Dextrin,  13,  162. 
Dextrose — see  Glucose. 
Dextrotartaric  Acid,  13. 
Dialysis  of  Alkaloids,  131,  134. 
Digitaleic  Acid— see  Digitalic  Acid. 
Digitalic  Acid,  13,  28. 
Digitalin,  125, 127, 128, 135  to  139,  141, 

143  to  145,  149,  150. 
Digitoleic  Acid — see  Digitalic  Acid. 
Dill  Oil,  107,  111. 
Distillation,  Fractional,  66. 
Dragendorff's   Method  with  Alka- 

loids,  131,  134,  136. 
Dragon's  Blood,  97,  103. 

ELATDIN,  formation  of,  75 
Elseoptenes,  104. 
Elafcerin,  136,  145,  154,  156. 


INDEX. 


189 


Emetia,  125,  128,  135  to  138,  141,  142, 

145,  149,  150. 

Emulsions,  formation  of,  74. 
Ergotina,  125,  128,  141,  145. 
Erucic  Acid,  13,  70. 
Essence  of  Mirbane — see  Nitroben- 

zole. 

Ether,  13,  179. 
Ethers,  Compound,  13. 
Ethylic  Alcohol,  176. 
Ethyl  Sulphates,  177. 
Eucalyptus  Oil,  107,  109,  113. 

FATTY  Acids,  13. 

Separation  from  Neutral  Fats, 

Non-volatile,  68. 

Volatile,  67. 
Fats,  72. 

Fennel  Oil,  107,  108,  109,  112. 
Ferric  Chloride,  as  Reagent  for  Al- 
kaloids, 148. 
Fixed  Oils,  72. 
Formic  Acid,  13,  55,  60,  75. 

Ether,  formation  of,  56. 
Fractional  Crystallization,  68. 

Fusion,  71. 

Saturation  and  Distillation,  66. 
Frankincense,  102. 
Fraxin,  154,  156. 
Frohde's  Reagent,  144, 
Fuchsin,  120. 
Fusel-Oil,  185. 

Fustic,   separation  of    Morintannic 
Acid  from,  35. 

GALANGAL  Oil,  107. 
Galbanum  Oil,  107. 
Gallic  Acid,  13,  3O. 
Gallotannic  Acid,  28. 
Gamboge,  97. 

Resin  of,  97, 103. 
Gambogic  Acid,  13,  41,  97. 
Gasolene,  119. 
Gelatin,  13,  16O. 
Gentianic  Acid,  13,  39. 
Gentianin — see  Gentianic  Acid. 
Gentian  Root,  separation  of   Gen- 
tianic Acid  from,  40. 
Gentisic  Acid — see  Gentianic  Acid. 
Gentisin — see  Gentianic  Acid. 
Geranium  Oil,  107, 113. 
Glucose,  168. 

Glucosides  (with  Alkaloids),  125. 
Glue — see  Gelatin. 

Glyceric  Acid,  resemblance  to  Lac- 
tic, 53. 
Glycerin,  13,  85. 

Determined  in  Soap,  91. 


Graham  and  Hof  mann's  Method,  131, 

Grape-seed  Oil,  72. 
Grape  Sugar,  168. 
Guaiacol,  116. 

Guaiac  Resin,  Separation  from  Gam- 
boge, 98, 103. 
Guaiacum,  98,  103. 
Guaiaretin,  formation  of,  98. 
Gum,  13,  161. 

Arabic,  161. 

Tragacanth,  162. 
Gum-resins,  93. 
Gun  Cotton — see  Nitrocellose. 

HAGER'S  Method  with  Volatile  Oils, 

111. 

Hazel-nut  Oil,  73. 
Hemp  Resin,  98,  103. 
Hemp-seed  Oil,  72,  77,  80,  81. 
Hesperidin,  145. 
Hippuric  Acid,   distinguished  from 

Benzoic,  43. 
Hop  Oil,  107,  109. 

Hydrastia,  125,  ,128,  138,  145,  146, 148. 
Hyoscyamia,  125,  128,  135  to  138, 142, 

144,145,  148  to  150. 

IGASURIA,  125,  128,  138,  145,  147, 148. 

Incense— see  Olibanum. 

Indian  Hemp — see  Hemp  Resin. 

India  Rubber — see  Caoutchouc. 

Indigo  Blue,  99,  103. 

Iodine  Solution,  as  Reagent,  139, 144. 

lodoform,  13,  177,  184. 

JALAP  Resins,  99. 
Jalapic  Acid,  100. 
Jalapin,  99, 103. 

Separation  from  Gamboge,  98. 
Jalapinol,  100. 
Jalapinolic  Acid,  100. 
Jasmin  Oil,  107. 
Juniper  Oils,  107,  108,  109,  113,  114. 

KINIC  Acid— see  Quinic  Acid. 
Kinotannic  Acid,  33. 
Kinovic  Acid— see  Quinovic  Acid. 
Kinovin — see  Quinovic  Acid. 
Kuphanilin,  120. 

LAC  (resin),  100,  103. 
Lactic  Acid,  13,  53. 
Lactoscope,  Vogel's,  84. 
Lactose,  171. 
Lactucin,  154, 156. 
Lard,  74. 

In  Butter,  83. 

Oil,  73,  76,  78,  80,  81. 


190 


INDEX. 


Laurie  Acid,  13,  70. 

Lavender  Oil,  107,  108,  110, 113,  114. 

Lead  Salts  of  Acids  separated,  59. 

Leather,  161. 

Lemon  Oil,  107  to  110,  113,  114. 

Limonin,  145. 

Linoleic  Acid,  13,  69. 

Liquid  Non- volatile  Acid,  53. 

Volatile  Acids,  55. 
Liquids,  Preliminary   Examination 
of,  12. 

MACE,  107,  109,  113. 
Magenta,  121. 

Maisch's  tests  for  Volatile  Oils,  110. 
Marjoram  Oil,  107,  109,  113. 
Malic  Acid,  13,  32. 
Mannite,  174. 
Mastic,  101,  103. 
Masticin,  101. 

Mayer's  tests    with  Volatile  Alka- 
loids, 124. 

Meconic  Acid,  13,  24. 
Meconin,  145. 
Metachloral,  183. 
Metapectic  Acid,  167. 
Metapectin,  167. 

Metatungstic  Acid,  as  Reagent,  141. 
Methylic  Alcohol,  13,  174. 
Milk  Albumen,  159. 

Commercial  Examination  of,  160. 

Determination  of  Fats  in,  84. 
Casein  in,  159. 

Quantitative  Analysis  of,  160. 

Sugar — see  Lactose. 
Mirbane,  Essence  of — see  Nitroben- 

zole. 

Molybdate,  as  Reagent,  141. 
Monophenylamin — see  Anilin. 
Morintannic  Acid,  13,  28,  35. 
Morphia,  126  to  128,  136  to  139,  141  to 

145,  147  to  150. 
Mustard  Oils,  73. 
Myristic  Acid,  13,  70. 

Alcohol,  95. 
Myrrh  Oil,  107. 

Resin,  101,  103. 

Separation  of,  from  Gamboge,  98. 

NABCEINA,  126  to  128,  136  to  138,  141 
to  150. 

Narcotina.  126  to  128,  135  to  138,  140 
to  145,  147  to  149. 

Nicotia.    123,   124,   128.   135  to  138, 
141  to  145,  148,  149. 

Nitric  Acid,  as  Reagent  for  Alka- 
loids, 147. 

Nitrite  of  Amyl,  186. 
Ethyl,  180. 


Nitrobenzole,  13,  112,  119. 
Nitrocellulose,  168. 
Nitrogenous  Neutral  Bodies,  157. 
Nitrophenic  acid,  13,  49,  51. 
Nitrous  Ether,  180. 
Non-drying  Oils,  73,  75. 
Non-volatile  Alkaloids,  125. 

Fat  Acids,  68. 
Nutmeg  Oil,  107,  111,  114. 

OENANTHYC  Acid,  67,  68. 
Oenanthylic  Acid — see  Oenanthyc. 
Oils,  Fixei,  13,  72. 

Volatile,  13,  104. 
Oleic  Acid,  13,  69. 
Oleo-resins,  93. 
Olibanum  (resin),  102. 
Olive  Oil,  73,  76,  77,  80,  81. 
Ononin,  145. 

Opiania,  126,  127,  129,  148. 
Opianyl — see  Meconin. 
Opium,  Separation  of  Meconic  Acid 

from,  24,  25. 
Orange  Flower  Oil,  107,  109,  113. 

Peel  Oil,  107,  109,  110,  113,  114. 
Organic  Compounds,  determined  as 

such,  11,  12. 
Origanum  Oil,  107. 
Otto-Stas'  Method   with  Alkaloids, 

130,  131. 
Ovalbumen,  158. 

PALMITIC  Acid,  13,  70. 
Papaverina,  126,  127,  129,  135  to  138, 

141  to  145,  149,  150. 
Paracumaric  Acid,  formation  of,  93. 
Parapectic  Acid,  166. 
Parapectin,  166. 
Parmelia    Parietina,    Chrysophanic 

Acid  from,  41. 
Parsley  Oil,  107,  109,  113. 
Patchouli  Oil,  110. 
Paytina,  126,  129,  138. 
Pectic  Acid,  166. 
Pectin,  13,  166. 
Pectose,  166. 
Pectous  Substances,  166. 
Pelargonic  Acid,  67.  68. 
Peppermint  Oil,   107,   109,  111,  112, 

114,  115. 

Pepper  Oil,  107,  114. 
Peru  Balsam,  102,  103. 
Petroleum  Naphtha,  13,  119. 
Phenic  Acid,  48. 
Phenol — see  Phenic  Acid. 
Phenylamin — see  Anilin. 
Phenylic  Alcohol — see  Phenic  Acid. 
Phenyl  Sulphuric  Acid— see  Sulpho- 

phenic. 


INDEX. 


191 


Phloridzin,  145,  155,  156. 
Phosphomolybdio  Acid,  as  Reagent, 

139,  140. 
Physostigmia,  126,  139,  135,  136,  138, 

141  to  145,  148,  150. 
Picramic  Acid,  52. 
Picric  Acid,  as  Reagent,  139. 

See  Mtrophenic  Acid. 
Picrotoxin,   126,  127,  129,  136  to  138, 

146. 

Pimaric  Acid— see  Colopholic  Acid. 
Pimento  Oil,  107. 
Pinic  Acid,  in  Colophony,  96. 
Piperidin,  141. 
Piperin,  126,  129,  134,  136,  137,  138, 

141  to  145,  147. 
Platinic  Chloride,    as   Reagent   for 

Alkaloids,  148. 

Podophyllum  Resin,  102,  103. 
Poppy-seed  Oil,  72,  77,  78,  80. 
Populin,  137,  145,  155,  156. 
Potassio    Mercuric   Iodide,    as   Re- 
agent, 139. 

Cadmic  Iodide,  as  Reagent,  141. 
Propylamin — see  Trimethylamia. 
Pseudomorphia,  126,    127,    129,   138, 

142.145,148. 
Pyrogalljc  Acid,  13,  32. 
Pyrogalline — Pyrogallol — see   Pyro- 

gallic  Acid. 
Pyroxyllon — see  Nitrocellulose. 

QUASSIN,  155,  156. 

Quercitannic  Acid,  27,  28. 

Quinia,  126,  129,  135  to  138,  140  to 

142,  144,  145,  148,  149,  150. 
Quinic  Acid,  13,  36. 
Quinidia,  126,  129,  135,  136,  138,  140, 

141,  142, 145,  149,  151. 
Quinone,  Formation  of,  37. 
Quinotannic  Acid,  13,  38,  33. 
Quinovic  Acid,  13,  38. 
Quinovin — see  Quinovic  Acid. 

RACEMIO  Acid,  13,  18. 
Rape-seed  Oil,  73,  76,  78,  80,  81. 
Resinifled  Oils,  105,  115. 
Resins,  13,  92. 

Determined  in  Soaps,  90. 
Roeadia,  126,  129,  138. 
Rhubarb,  Chrysophanic  Acid  from, 

41. 

Ricinoleic  Acid,  13,  69. 
Rodgers   and   Girdwood's    Method, 

130,  132. 
Rosanilin,  121. 

Rosemary  Oil,  107,  109,  111,  113,  114. 
Rose  Oil,  107,  109,  111,  113,  114. 
Rosewood  Oil,  107. 


Rosin  Oil,  96. 

Rue  Oil,  108,  109,  111,  113. 

SABADILLIA,  126,  129,  142,  148. 
Sabadilla  Seeds,  V eratric  Acid  from, 

47. 

Saccharose — see  Sucrose. 
Salicin,  126,  129,  136,  137,  138,  145. 
Salicylic  Acid,  13,  47. 
Sandarac,  102,  104. 
Sanguinarin,  142. 
Santalic  Acid,  13,  42. 
Santalin — see  Santalic  Acid. 
Santonin,  137. 

Saponification,  Means  of,  75. 
Saponin,  126,  129,  138. 
Sarcolactates,  54. 
Sarsaparillin,  146,  156. 
Sassafras  Oil,  108,  109,  110. 
Saturation,  Fractional,  60. 
Savine  Oil,  108,  109,  114. 
Scammonin — see  Jalapin. 
Scammony,  102. 
Seal  Oil,  80. 

Secalin— see  Trimethylamia. 
Senagin,  146. 

Senna  Resin,  Separation  from  Gam- 
boge, 98,  104. 

Separation  of  Acids,  xas  Lead  Salts, 
59. 

Alkaloids  from  other  matters,  130. 
each  other,  156. 
G-lucosides,  156. 

Fixed  Oils,  85. 

Non-volatile  Fat  Acids,  71. 

Resins,  103. 

Solids  from  Liquids,  12. 

Volatile  Fat  Acids,  66,  68. 

Volatile  Oils,  105. 
Seralbumen,  158. 
Sesame  Oil,  73,  76,  80,  81. 
SheU  Lac,  101. 
Soaps,  13,  87. 
Solania,  126,  127, 129,  136,  138,  141  to 

145,  147,  148,  151. 
Solids,    Preliminary    Examination 

of,  11. 
Solid  Volatile  Acids,  42. 

Non-volatile  Acids,  14. 
Soluble  Starch,  164. 
Smilacin,  146. 
Spermaceti,  74. 
Spearmint  Oil,  108,  110. 
Spirit  of  Nitrous  Ether,  180. 
Starch,  13,  164. 
Starch  Sugar — see  Glucose. 
Stas  and  Otto's  Method  with  Alka» 

loids,  130. 
Stearic  Acid,  13,  7O. 


192 


INDEX. 


Stearoptenes,  104. 
Storax  Resin,  103. 

Strychnia,  126,  137,  139,  135,  137,  138, 
140  to  144,  146,  151. 

Test,  146,  149. 
Styracin,  102,  103. 
Succinic  Acid,  45. 
Sugars,  13,  1G8. 

Sulphuric   Acid,    as   Reagent,    144, 
155,  156. 

See,  also,  under  Glucosides. 
Sunflower  Oil,  73,  77. 
Sweet  Spirits  of  Nitre— see  Spirits 

Nitrous  Ether. 

Sylvic  Acid,  in  Colophony,  96. 
Syringin,  136, 146. 

TALLOW,  74. 

in  Butter,  83,  83. 
Tannic  Acid,  13,  18,  146. 

distinguished  from  Gallic,  31. 

as  Reagent,  139,  143. 
Tannic  Acids,  26. 
Tanoxylic  Acid,  27. 
Tansy  Oil,  108,  109,  114. 
Taraxacin,  156. 
Tartaric  Acid,  13,  14. 
Tea,  Black,    Separation   of   Boheic 

Acid  from,  36. 
Thebaina,  126,  137,  139,  135  to  138, 

143, 143,  146,  149,  151. 
Theobromina,  127,   129,   136  to  139, 

141,  143,  146,  148,  149,  151. 
Thyme  Oil,  108,  109,  114. 
Tolu  Balsam.  103. 


Toluidin,  120,  121. 

Tolu  Resin,  Separation  from  Gam- 
boge, 98. 

Tragacanth,  162. 

Trimethy  lamia,  123,  124 

Trinitrophenic  Acid  —  see  Nitro- 
phenic. 

Trommer's  Sugar  Test,  169. 

USLAR  and  Erdmann's  Method,  130. 
133. 

VALERIANIC  Acid — see  Valeric. 
Valerian  Oil,  108,  109,  111,  113,  115. 
Valeric  Acid,  13,  60,  63. 
Vanillin,  156. 
Veratria,  137,  139,  135  to  139,  140  to 

144,  146,  148,  151. 
Veratric  Acid,  13,  47. 
Vogel's  Lactoscope,  84. 
Volatile  Bases,  130. 
Fat  Acids,  67. 

WALL  Lichen— see  Parmelia  p. 
Walnut  Oil,  73,  77. 
Wax,  Bees',  74. 
Whale  Oil,  73,  78. 
Wintergreen  Oil,  108,  110. 
Wormseed  Oil,  108  to  111,  114. 
Wormwood  Oil,  108,  109,  111,  114. 

XTLTDIN,  130. 

YARROW  Oil,  108. 

Ylang  Ylang  (Oil),  108,  114. 


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MinifLe's  Geometrical  Drawing. 

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QUARTZ    OPERATOR'S   HAXD-BOOK.    P,y  P.  M.   RANDALL.      New 

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Joynson  on  Machine  G-earing. 

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THE  MECHANIC'S  AND  STUDENT'S  GUIDE  in  the  designing  and  Con 
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ELKCTRO-BALLISTIC    MACHINES,  and  the   Schultz  Chronoscope.     By 
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VAN    NOSTKAND'S     SCIENCE     SERIES. 


It  is  the  intention  of  the  Publisher  of  this  Series  to  issue  them  at 
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I.  CHIMNEYS  FOR  FURNACES,  FIRE-PLACES,  AND  STEAM  BOILERS.    By 

R.  ARMSTRONG,  C.E. 

II.  STEAM  BOILER  EXPLOSIONS.    By  ZERAH  COLBURN. 

HI.  PRACTICAL  DESIGNING  OF  RETAINING  WALLS.  By  ARTHUR  JACOB 
A.  B .    With  Illustrations. 

IV.  PROPORTIONS    OF    PINS    USED    IN    BRIDGES.     By    CHARLES    E 
BENDER,  C.E.     With  Illustrations. 

V.  VENTILATION  OF  BUILDINGS.  By  W.  F.  BUTLER.  With  Illustrations, 

VI.  ON  THE  DESIGNING  AND  CONSTRUCTION  OF  STORAGE  RESERVOIRS. 
By  ARTHUR  JACOB.     With  Illustrations. 

VII.  SURCHARGED  AND   DIFFERENT  FORMS  OF  RETAINING  WALLS 
By  JAMES  S.  TATE,  C.E. 

VHI.  A  TREATISE  ON  THE  COMPOUND  ENGINE.    By  JOHN  TURNBULLI 

With  Illustrations. 

IX.  FUEL.     By  C.  WILLIAM  SIEMENS,  to  which  is  appended  the  value  of 
ARTIFICIAL  FUELS  AS  COMPARED  WITH  COAL.    By  JOHN  WORM" 
ALD,  C.E. 

X.  COMPOUND  ENGINES.    Translated  from  the  French  of  A.  MALLET. 

Illustrated. 

XL  THEORY  OF  ARCHES.    By  Prof.  W.  ALLAN,  of  the  Washington  and 
Lee  College.     Illustrated. 

Xn.  A  PRACTICAL  THEORY  OF  VOUSSOIR  ARCHES.  By  WILLIAM  CART, 
C.E.    Illustrated. 


D.  VAN  NOSTEAND.  23 


XIII.  A  PRACTICAL  TREATISE  ON  THE  GASES  MET  WITH  IN  COAX. 
MINES.     By  the  late  J.  J.  ATKINSON,  Government  Inspector  of 

Mines  for  the  County  of  Durham,  England. 

XIV.  FRICTION  OF  AIR  IN  MINES.    By  J.  J.  ATKINSON,  author  of  "  A 
Practical  Treatise  on  the  Gases  met  with  in  Coal  Mines." 

XV.  SKEW  ARCHES.      By  Prof.  E.  W.  HYDE,  C.E.    Illustrated  with 
numerous  engravings  and  three  folded  plates. 

XVI.  A  GRAPHIC  METHOD  FOR  SOLVING  CERTAIN  ALGEBRAIC  EQUA- 
TIONS.   By  Prof.  GEORGE  L.  VOSE.    With  Illustrations. 

XVH.  WATER  AND  WATER  SUPPLY.  By  Prof.  W.  H.  CORFIELD, 
M.A.,  of  the  University  College,  London. 

XVIH.  SEWERAGE  AND  SEWAGE  UTILIZATION.  By  Prof.  W.  H. 
CORFIELD,  M.A.,  of  the  University  College,  London. 

XIX.  STRENGTH  OF  BEAMS  UNDER  TRANSVERSE  LOADS.      By  Prof. 
W.  ALLAN,  author  of  "  Theory  of  Arches."    With  Illustrations 

XX.  BRIDGE  AND  TUNNEL  CENTRES.      By  JOHN  B.  MCMASTERS^ 
C.E.    With  Illustrations. 

XXI.  SAFETY  VALVES.    By  RICHARD  H.  BUEL,  C.E.    With  Illustra- 
tions. 

XXn.  HIGH  MASONRY  DAMS.  By  JOHN  B.  MCMASTERS,  C.E. 
With  Illustrations. 

XXfll.  THE  FATIGUE  OF  METALS  under  Repeated  Strains,  with 
various  Tables  of  Results  of  Experiments.  From  the  German  of 
Prof.  LUDWIG  SPANGENBERG.  With  a  Preface  by  S.  H.  SHRKVE, 
A.M.  With  Illustrations. 

XXIV.  A  PRACTICAL  TREATISE  ON  THE  TEETH  OF  WHEELS,  with 
the  theory  of  the  use  of  Robinson's  Odontograph.   By  S.  W.  ROBIN- 
SON, Prof,  of  Mechanical  Engineering,  Illinois  Industrial  University. 

XXV.  THEORY  AND    CALCULATIONS  OF  CONTINUOUS  BRIDGES.    By 
MANSFIELD  MERRIMAN,  C.E.     With  Illustrations. 

XXVI.  PRACTICAL  TREATISE  ON  THE  PROPERTIES   OF  CONTINUOUS 
BRIDGES.    By  CHABLES  BENDER,  C.E. 


2i  V.    VAN  NO  STRAND. 


XXVII.    ON  BOILER  INCRUSTATION  AND  CORROSION.    By  F.  J.  ROWAN. 

With  Illustrations. 

^SXVIII.     ON  TRANSMISSION  OF  POWER  BY  WIRE  ROPE.      By  ALBERT 
W.  STAHL.     With  Illustrations. 

£XIX.     INJECTORS.     The  Theory  and  Use.     Translated  from  the  French 
of  M.  LEON  POCHET.     With  Illustrations. 

XXX.  TERRESTRIAL  MAGNETISM  AND  THE  MAGNETISM  OF  IRON  SHIPS. 
By  Prof.  FAIRMAN  ROGERS.     With  Illustrations. 

XXXI.  THE  SANITARY  CONDITION  OF  DWELLING  HOUSES  IN  TOWN 
AND  COUNTRY.     By  GEORGE  E.  WARING,  Jr.     With  Illustrations. 

XXXII.  CABLE  MAKING  OF  SUSPENSION  BRIDGES  AS  EXEMPLIFIED  IN 
THE  EAST  RIVER  BRIDGE.     By  WILHELM   HILDENBRAND,  C.    E. 

With  Illustrations. 

XXXIII.  MECHANICS  OF  VENTILATION.     By  GEORGE  W.  RAFTER,  Civil 

Engineer. 

XXXIV.  FOUNDATIONS.     By  Prof.  JULES  GAUDARD,  C.  E.     Translated 
from  the  French,  by  L.  F.  VERNON  HARCOURT,  M.  I.  C.  E. 

XXXV.  THE  ANEROID  BAROMETER,  ITS  CONSTRUCTION  AND  USE,    Com- 
piled by  Prof.  GEORGE  W.  PLYMPTON.     Illustrated. 

XXXVI.  MATTER  AND  MOTION.    By  J.  CLERK  MAXWELL,  M.  A. 

XXXVII.  GEOGRAPHICAL  SURVEYING.     Its  Uses,  Methods  and  Results. 
By  FRANK  DE  YEAUX  CARPENTER,  C.  E. 

XXXVIII.  MAXIMUM  STRESSES  IN  FRAMED  BRIDGES.     By  Prof.  WM. 
CAIN,  A.  M.,  C.  E.     Illustrated. 

XXXIX.  A  HAND  BOOK  OF  THE   ELECTRO  MAGNETIC  TELEGRAPH. 
By  A.  E.  LORING.    Illustrated. 

XL.    TRANSMISSION  OF  POWER  BY    COMPRESSED   AIR.       By   ROBERT 
ZAHNER,  M.  E.     Illustrated. 

XL1       ON  THE  STRENGTH  OF  MATERIALS.    By  WM.  KKNT,  C.  E. 

XLII.     VOUSSOIR  ARCHES    APPLIED  TO   STONE  "BRIDGES,   TUNNELS,   ETC. 
By  Prof.  W.  Cain. 


UNIVER$IT$W  CALIFORNIA  LIBRARY 
BERKELEY 


Return  to  desk  from  which  borrowed. 
This  book  is  DUE  on  the  last  date  stamped  below. 


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U 


DEC  18  1961 


LD  21-100m-9,'47(A5702sl6)476 


